New build underground gas duct to meter box

[ruggers]

I've laid my 63mm underground yellow gas duct for a new build and i have it coming from horizontal underground with a sweeping bend up vertically to the hole under the built in external meter box.

 

The electric one has a red and white hockey stick to complete the transition between duct and meter box, but I cant see anything online for the same with gas.

 

Looking at completed wall boxes on neighbour’s houses they just have a white plastic conduit coming out the bottom of the gas meter box into the ground.

 

Does the gas company provide this?

 

Is there a coupling for the 63mm to stick?

 

Hoping to not have to dig down through compacted type 1 to add a plast sweeping bend when the yellow duct already does this with the draw cord in.

[JohnMo]

Sorry not answering your question - but more or an observation.

 

Why are you installing gas on a new build? Install a heat pump and save your self a fortune in running costs. Add a battery/PV and save more.

 

Our new build was completed in 2021, with gas boiler. After a year or so fully optimising how it it ran, I added an ASHP specifically for cooling the floor. Operated a hybrid system. Realised, with standby charge for gas and the great cop from a heat pump, the boiler had to go. Since added more PV and battery and pay almost nothing for energy even in NE Scotland.  Gas is last century.

[saveasteading]

Yes, I think the current rule of thumb is to keep gas or oil if already in place but use ashp if all new.

That may change according to what happens re the Iran situation.

 

But putting in a gas pipe just in case makes some sense. Have you laid the yellow warning tape above it in the trench?

If in doubt, bring it through a 110mm pipe bend and close both off with plastic and sticky tape.

Edited Saturday at 17:16 by saveasteading

[ruggers]

@saveasteading

I'm on the old 2022 regs so i can choose gas or electric heating, solar is a choice and overheating hasnt came in by then.

 

The yellow duct has been in place for over a year, it just comes up from 600mm below to up against the wall. Its £290 to get connected.

[ruggers]

8 hours ago, JohnMo said:

Sorry not answering your question - but more or an observation.

 

Why are you installing gas on a new build? Install a heat pump and save your self a fortune in running costs. Add a battery/PV and save more.

 

Our new build was completed in 2021, with gas boiler. After a year or so fully optimising how it it ran, I added an ASHP specifically for cooling the floor. Operated a hybrid system. Realised, with standby charge for gas and the great cop from a heat pump, the boiler had to go. Since added more PV and battery and pay almost nothing for energy even in NE Scotland.  Gas it last century.

2021 wasn't last century 😂.

For what it costs i just want to run gas in. I wish there were more gas ashp hybrid units.

 

Ashp wont save me any more theyre almost identical in running costs I've been going over it for years and nothings changed. Its a total nightmare i hate heat pumps and battery and solar before I've even lived in the house.

Tempted to sell it at the end and stay in an old house with gas combi and not have to monitor how much water i use and pausing heating because its 4pm to 7pm peak rate.

 

I'm just going round in circles with it and over the 4 years I've been told heat pumps are the future and the prices will come down, they've just increased by 15%

 

I'll likely have to fit an ashp to handle the low peoperty heat loss and minimise short cycling better than gas but i really dont want one. It just means the battery situation becomes twice as expensive so not woerh it for me.

 

I've put 4.8kw of South facing solar on, thats the most i can put on the roof. Battery adds 2 grand, or 3 grand if i add the gateway for off grid back up. Due to my low usage I'd save £220 a yr using octopus cosy, thats not a big enough saving for a decent roi.

 

Cant get on anything cheaper than cosy without an EV which i wont be buying. EV is the only way to make a battery roi by unlocking super off peak rates.

 

The idea of having weather compensated heating is to let it run 24/7 and have a nice steady comfortable house, but energy prices on tou tariffs just goes against it all and makes us run sumilar to on off if we're having to use set backs in the peak slots. If electric cost 4p per kwh, we'd just run it as we please.

 

My price was for a 9.4kwh battery which is enough for my house, but add an ashp, then i need twice as much battery, so twice as much outlay, which still doesnt help the roi. Cycling a smaller 9.4kwh  multiple times ler day just halfs its life span

 

If you have an EV and can stick 10kw+ of panels on the roof and install a battery yourself then its all good.

 

Solar doesnt help a heat pump when you need it in winter. In summer you only need to heat dhw. Solar diverts a waste of money if you can export for 12 to 16p per kwh, its better to heat dhw quicker and more efficiently with the ashp in summer.

 

I'd need a scop of 4.15 to equal my 90% efficient gas price vs 25p standard electric cost.

 

Cosy off peak 14.5p

 

Ashp is average scop 4, so its 400% efficient, but Gas heats is 4x cheaper  and heats dhw 3x faster at any outdoor temperature and due to the cost, you can just set water constant 24 hrs a day and not worry about tou cheap slots. We like 10 minute showers, 3 of them and the tanks nearly empty.

 

Engineers charge £100 more for a heat pump service vs gas which wipes out the annual savings.

 

Will an outdoor heat pump exposed to the elements last as long as an indoor gas boiler?

 

Same brand boilers 12 yr warranty vs heat pumps 7yrs. The manufactures cant have faith in the product.

 

The only reason I'll end up installing an ashp, is if it will run a low heat loss property better than a viessmann 200 11kw boiler at its lowest modulation of circa 2kw. But most heat pumps ive seen are 2.1kw min output too.

[JohnMo]

7 hours ago, ruggers said:

2021 wasn't last century 😂.

True, but my decision to install was flawed I should have installed a heat pump.

 

7 hours ago, ruggers said:

Cosy off peak 14.5p

Currently 10p.

 

7 hours ago, ruggers said:

Solar diverts a waste of money if you can export for 12p

Very true, I don't have one, just export what I don't use 

 

7 hours ago, ruggers said:

But most heat pumps ive seen are 2.1kw min output too.

My 4kW will do 0.9kW, but must admin never seen it go below 2kW.

 

7 hours ago, ruggers said:

century 😂.

For what it costs i just want to run gas in. I wish there were more gas ashp hybrid units

But you pay nearly as much in annual standing charges as you do for gas. So effective cost per kWh is nearly double. That's when I realised the gas pipe meter had to go.

 

So the real cost of gas is actually close to or more expensive than the electricity, to power a heat pump on an annual basis (Cosy 10p) plus you should be getting a CoP of 4.0 to 4.5.maybe better. Even at normal cost rate of 25p you really only need a CoP of around 2.5p to break even.

 

My system is super simple now. Immersion to do DHW, a direct cylinder can be as cheap as chips compared to a heat pump one. 

 

Heat pump direct to UFH, no mixer or pump, no zone valves. I have room temperature monitoring via a good UFH controller, but a single on/off signal to heat pump set to where I want house temp. A single switch to move from heat to cool.

 

Cylinder £500

Heat pump £2100 (including vat)

UFH controller and room monitors came to a around £200 from eBay.

 

But a Viessmann is a good boiler can make a very simple setup, just get a 4 pipe boiler job done. Either weather compensation or set flow to 30 to 35 and let the controller look after house temperature. But install a heat pump cylinder to get condensation mode through our the DHW heating cycle.

[saveasteading]

Understood. And you've got the gas pipe there. If that was me I'd just ensure that you can change over in the future without too much disruption.

[Bornagain]

14 hours ago, ruggers said:

2021 wasn't last century 😂.

For what it costs i just want to run gas in. I wish there were more gas ashp hybrid units.

 

Ashp wont save me any more theyre almost identical in running costs I've been going over it for years and nothings changed. Its a total nightmare i hate heat pumps and battery and solar before I've even lived in the house.

Tempted to sell it at the end and stay in an old house with gas combi and not have to monitor how much water i use and pausing heating because its 4pm to 7pm peak rate.

 

I'm just going round in circles with it and over the 4 years I've been told heat pumps are the future and the prices will come down, they've just increased by 15%

 

I'll likely have to fit an ashp to handle the low peoperty heat loss and minimise short cycling better than gas but i really dont want one. It just means the battery situation becomes twice as expensive so not woerh it for me.

 

I've put 4.8kw of South facing solar on, thats the most i can put on the roof. Battery adds 2 grand, or 3 grand if i add the gateway for off grid back up. Due to my low usage I'd save £220 a yr using octopus cosy, thats not a big enough saving for a decent roi.

 

Cant get on anything cheaper than cosy without an EV which i wont be buying. EV is the only way to make a battery roi by unlocking super off peak rates.

 

The idea of having weather compensated heating is to let it run 24/7 and have a nice steady comfortable house, but energy prices on tou tariffs just goes against it all and makes us run sumilar to on off if we're having to use set backs in the peak slots. If electric cost 4p per kwh, we'd just run it as we please.

 

My price was for a 9.4kwh battery which is enough for my house, but add an ashp, then i need twice as much battery, so twice as much outlay, which still doesnt help the roi. Cycling a smaller 9.4kwh  multiple times ler day just halfs its life span

 

If you have an EV and can stick 10kw+ of panels on the roof and install a battery yourself then its all good.

 

Solar doesnt help a heat pump when you need it in winter. In summer you only need to heat dhw. Solar diverts a waste of money if you can export for 12 to 16p per kwh, its better to heat dhw quicker and more efficiently with the ashp in summer.

 

I'd need a scop of 4.15 to equal my 90% efficient gas price vs 25p standard electric cost.

 

Cosy off peak 14.5p

 

Ashp is average scop 4, so its 400% efficient, but Gas heats is 4x cheaper  and heats dhw 3x faster at any outdoor temperature and due to the cost, you can just set water constant 24 hrs a day and not worry about tou cheap slots. We like 10 minute showers, 3 of them and the tanks nearly empty.

 

Engineers charge £100 more for a heat pump service vs gas which wipes out the annual savings.

 

Will an outdoor heat pump exposed to the elements last as long as an indoor gas boiler?

 

Same brand boilers 12 yr warranty vs heat pumps 7yrs. The manufactures cant have faith in the product.

 

The only reason I'll end up installing an ashp, is if it will run a low heat loss property better than a viessmann 200 11kw boiler at its lowest modulation of circa 2kw. But most heat pumps ive seen are 2.1kw min output too.

We live in our extremely well insulated 200m2 self build that we did in 2011.

 

Heating is by a 5 KW Vaillant Heat Pump that runs for 7 hrs per night on an economy 7 tariff. When we get extremely cold weather, perhaps 5 days per year, it is typically very sunny and we also run the heat pump on daytime solar PV to consume the excess production.

 

The downstairs temperature is always in the range 20.5-21c and it’s around 19c in the unheated bedrooms.

 

Heat pumps most certainly can work in a modern house without needing a battery.

[JohnMo]

29 minutes ago, Bornagain said:

Heat Pump that runs for 7 hrs per night on an economy 7 tariff

That's what we did before battery and smart meter (last August)

[ruggers]

On 03/05/2026 at 08:44, JohnMo said:

My 4kW will do 0.9kW, but must admin never seen it go below 2kW.

Why does it not go below 2kW? Viessmann and Vaillant and many other well know state 2.1Kw minimum compressor output which I find strange.

Forgetting costs of running, does the heat pump provide any difference in comfort or less short cycling than when you had the boiler, and if it does, is it purely because it can modulate lower than the boiler you had?

 

On 03/05/2026 at 08:44, JohnMo said:

You should be getting a CoP of 4.0 to 4.5.maybe better. Even at normal cost rate of 25p you really only need a CoP of around 2.5p to break even.

How does a cop of 2.5 break even on a gas boiler. gas 5.4p at 100% efficient, 6.1p at 90%, electric 25p, scop 4.1 required and even in summer you wont get a cop of over 4 on dhw which ruins the scop. An 11Kw boiler will provide 18Kw for DHW vs 6Kw heat pump, but it isn't going to change between summer and winter temperatures. My figures indicate gas cheaper and quicker on dhw and ashp slightly cheaper on space heating.

On 03/05/2026 at 08:44, JohnMo said:

 

My system is super simple now. Immersion to do DHW, a direct cylinder can be as cheap as chips compared to a heat pump one. 

Why do you choose immersion which is only 100% efficient vs the heat pump which is much quicker to heat and 250-360% ?

Are you just running on off controls for a fixed flow temperature like you mentioned?

[ruggers]

@Bornagain Sounds like a well built house. Do you know what your total heat loss was?

 

What size hot water cylinder did you choose?

Mines going to be exactly 200m2 too, floors, cold loft, 2.4m ceilings. UFH and radiators, MVHR.
4.8kw of almost south facing solar and anti sun glazing in the South windows. I'm applying a lot of detail to air tightness but I just wouldn't expect it to retain heat all day like yours. I'm designing the the heating system to have a max flow temperature of 35C at dt5.

 

How big is your PV system?

 

I've nothing against heat pumps and home battery, its just that the more electric I convert to, the bigger the battery needs to be plus the inverter to handle it all. To get a decent ROI, youneed to be on a time of use tariff and if the battery is undersized, you end up paying for peak or day rate, and with everything electric, I'd need a bigger inverter.

I had a company highly rated add some in roof PV to my build as a late decision, and just for once I wanted to not have to research it all and put the trust in a company, they were saying 90% of customers have a 3.6kw inverter, then I realised I'd need bigger with an ASHP and possible induction hob and electric oven, so they said 5kw hybrid inverter and they'll do the G99 to DNO. But looking at it again, 2 or 3 hobs in use with the oven on puts me above the 5Kw, so in 4-7pm peak rate which is 45p, I'd be in it every day even with the heat pump in set back.

[JohnMo]

5 hours ago, ruggers said:

Why does it not go below 2kW?

Not exactly sure, asked AI and looked at my performance and said it was running at minimum stable refrigeration limits. Possibly as a result of thick screed, widely spaced pipes UFH. Plus the floor acting as huge buffer quite happy to take all the heat it can get.

 

5 hours ago, ruggers said:

Forgetting costs of running, does the heat pump provide any difference in comfort or less short cycling than when you had the boiler,

I had an over sized heat pump which didn't modulate well, once setup it didn't short cycle, it did cycle but in a controlled manner. But I found any cycling hits efficiency, so typically when running ASHP would get a CoP of say 5, but standby losses dropped that down to 4 over the 24 hrs. My boiler I found a sweet spot the boiler liked and floor didn't over heat the house via overshoot and used a 0.1 Deg hysterisis thermostat and fixed flow temp of around 36 degs.  Would get 4 to 12hrs run time depending on outside temperature then off for 12 to 18 hrs.

 

5 hours ago, ruggers said:

How does a cop of 2.5 break even on a gas boiler. gas 5.4p at 100% efficient, 6.1p at 90%, electric 25p, scop 4.1 required and even in summer you wont get a cop of over 4 on dhw which ruins the scop

Gas isn't really 6p, it's 6p plus a proportion of standing charge. Your standing charge is around £100 per year, so if you use £100 of gas (£200 per year £100+100), your unit price of gas is really 12p. If you use £200 of gas your unit price for gas reduces and so on.  ASHP is one standing charge for electric (which have to pay if you have any electric in the house, gas boiler is two standing charges.

 

5 hours ago, ruggers said:

DHW - Why do you choose immersion which is only 100% efficient

I was using less than a £100 on gas but getting nearly £200 bill running hybrid mode (12p per kWh). I pay 10p for off peak electricity, so just use an immersion. It's easy and it's cheaper than gas in real terms. Plus I generate more PV than I can export 9 months of the year, so do most my heating around 1pm when electric is cheap and/or I have excess PV that would be clipped instead of exported.

5 hours ago, ruggers said:

200m2 too, floors, cold loft, 2.4m ceilings. UFH and radiators, MVHR

Our house is similar but single storey fully vaulted ceiling everywhere so our heat losses will be worse than yours (plus we have private water and sewage treatment all taking electric) we have a 13kW and it does fine even when we get -9, maybe take in a little electric at 25p.

 

I would look at typical winter days, which are around 7 degs, even running last night (5 degs) the heat pump was getting a CoP of 6.3. 3 hrs of that in a cheap periods so nothing coming out of the battery.

 

5 hours ago, ruggers said:

4.8kw of almost south facing solar, 3.6kW hybrid inverter

Your installer went for an easy install and zero discussion with DNO. Our battery has a 6kW inverter we may draw a little expensive electric in at Christmas but nothing most the year. If it does it's for seconds not hours. Hobs aren't a constant power draw they switch on off constantly.

[Mr Punter]

I have used black gas hockey stick.  Tricky to get hold of.

 

[Bornagain]

19 hours ago, ruggers said:

@Bornagain Sounds like a well built house. Do you know what your total heat loss was?

 

What size hot water cylinder did you choose?

Mines going to be exactly 200m2 too, floors, cold loft, 2.4m ceilings. UFH and radiators, MVHR.
4.8kw of almost south facing solar and anti sun glazing in the South windows. I'm applying a lot of detail to air tightness but I just wouldn't expect it to retain heat all day like yours. I'm designing the the heating system to have a max flow temperature of 35C at dt5.

 

How big is your PV system?

 

I've nothing against heat pumps and home battery, its just that the more electric I convert to, the bigger the battery needs to be plus the inverter to handle it all. To get a decent ROI, youneed to be on a time of use tariff and if the battery is undersized, you end up paying for peak or day rate, and with everything electric, I'd need a bigger inverter.

I had a company highly rated add some in roof PV to my build as a late decision, and just for once I wanted to not have to research it all and put the trust in a company, they were saying 90% of customers have a 3.6kw inverter, then I realised I'd need bigger with an ASHP and possible induction hob and electric oven, so they said 5kw hybrid inverter and they'll do the G99 to DNO. But looking at it again, 2 or 3 hobs in use with the oven on puts me above the 5Kw, so in 4-7pm peak rate which is 45p, I'd be in it every day even with the heat pump in set back.

The house is ICF with a wall u value of 0.15, windows and doors are all triple glazed u value of 1.0, the floor slab is on top of 300mm of EPS and there is over 600mm of insulation in the loft, we also have an MVHR system.

 

The only heating is UFH in the downstairs floor slab, we have no heating upstairs.

 

Heat loss is around 2kw @ -3c.

 

2kw x 24 hrs =48kwhrs, a 5 kw heat pump running for 7 hrs overnight generates 35kwhr, however when the weather is really cold we sometimes run the heat pump during the day powering it with PV.

 

We have a humongous 500 litre thermal store, if it needed replacing it would be swapped to around 350 litre dhw cylinder.

 

We have 7.74 kw of PV and 14kwhr of battery.

 

We have had the battery through 4 complete winters and have never run out of charge, the only times we have come close have been Christmas days with no sun, this is because the house is full and we do a lot of cooking with two ovens running for hours.

 

We have a 3.68kw grid tied inverter connected to the original FiT PV system plus another 4.4kw inverter connected to the battery and MPPTs

 

In our experience the maximum instantaneous demand for electricity is very very rarely above 5kw, we are on an E7 tariff and have only bought 44kwhrs of peak electricity in the last twelve months.

If you want to talk then drop me a message and I’ll give you a ring.

 

 

 

 

 

[ruggers]

@Mr Punter thanks for the image. Your yellow duct looks different to mine, I've used a 63mm ones as Northern gas specified, its corrugated on the outside. The don't seem as strict as other companies and not mentioned any hockey sticks but i have asked the question so there's no surprises on the day if i do choose to install it.

 

What does your gas power in the home and do you have a low energy/low temperature heating system?

 

Never seen 3 wall boxes before.

Bricks look the same as mine smoked branco and staffy blues.

[ruggers]

@JohnMoJohnMo what thickness of slab do you have, I'm going to have 55-60mm cemfloor.

 

Is your dhw set to constant or only heats in the cheap slots? I was focusing a bit too much on cylinder standing losses becauae many of them at 1.9 to 2.3kw/24hrs, and SAP only recognises this, but its based on stored water at around 70 degrees, not 48-50C which lowers the dt when placed in a 21 degree room.

 

I need to select battery or no battery to complete the pv 1st fix install, along with inverter size but ideally I'd live in the house for a year first to see its real behaviour and then decide. The solar company prefer hanchu systems but they only do 5.14 and 9.4kw battery, with i think its 3.6, 5 and 7kw inverters.

They did offer another 2 types of inverter but one was seriously expensive.There's the option of gateway for off grid back up for another £1k which if added on later i was told is a bit trickier and wouldnt be as cheap retrofitted.

 

I take it you have a large array but are limited on annual export? I'd have thought it was still cheaper to use the ashp to heat dhw than an immersion.

 

I understand that the cooking appliances modulate but it just feels like in winter, dark nights with a family to cook for in peak slot that with lights on, tv, oven and hob, i could easily be pushing above 5kw peaks which would daily push me into peak prices, even in spring and autumn or cloudy summer days.

 

I've been meaning to drop you a message and come back to our old conversation around my mvhr and heat loss as I've got a bit lost with it all and lost faith in the heat loss software which has updated its software and changed all sorts of figures that i had a good understanding of. I rhink i found the spreadsheet you mentioned but didnt find it very user friendly 

 

[Mr Punter]

The yellow is gas pipe laid directly in the ground.  The pic is from a development of 3 flats.  2 of the boxes feed the supplies round to the back of the building.

[JohnMo]

1 hour ago, ruggers said:

JohnMoJohnMo what thickness of slab do you have, I'm going to have 55-60mm cemfloor

100mm

 

1 hour ago, ruggers said:

dhw set to constant or only heats in the cheap slots?

Cheap slots, 1pm (cheap plus solar likely) and between 4am and 7am only. Heat to approx 50 degs.

 

1 hour ago, ruggers said:

take it you have a large array but are limited on annual export?

Have around 9kW in different directions can produce around 6.5kW at lunch time. But export is gagged at 3.6kW. Use battery to make best use of solar so as little clipping happens as possible.

 

1 hour ago, ruggers said:

still cheaper to use the ashp

Did some back to back testing, and found there was very little in it, in real life. Found heat pump start doing DHW heating earlier than really needed, so you end up heat the pipe runs to cylinder the cylinder gets steered up the thermal currents etc.  immersion just dies what it needs too.

 

1 hour ago, ruggers said:

pushing above 5kw peaks which would daily push me

I would go 5kW inverter, we have 6kW and zero issue really taking in expensive tariff 

 

The spreadsheet from Jeremy Harris, on here is pretty good easy to input.