PeterW

Sounds like the bladder has perished on the expansion vessel. You can check it yourself if you have a tyre pressure gauge ..? Top of the expansion vessel there will be a black cap - under it is a standard car tyre Schraeder valve. Just push the tyre pressure gauge onto the valve and read the pressure. It should be 3 Bar (pre-charge will be on the cylinder somewhere) and if it’s below that then get the foot pump out !! Don’t be tempted to run an air line to it - you’ll split the bladder ... If it is zero then you may struggle to pump it up. Turn the water off at the mains, open a hot tap and then try again.

If you really only want a kilo I would send you some but tbh it will keep in a plastic rubble bag and you can add it to all your mixes.

It’s £16 for a 25kg bag in Jewsons....

No - your water hammer is because there is no expansion anywhere in the system. What I would also have checked (first...) is that the Megaflo expansion tank is at 3 bar. Very rare to get water hammer in a sealed system as there is usually a route to expansion somewhere. Has the tank and reducer been checked or serviced recently ..??

I don’t agree but for a first build you need to be on top of everything and there is very little slack in a TF or SIPs schedule.

So fit a hammer arrestor on the incoming cold water. A 2 litre potable expansion vessel is change of £30, it’s less than an hour to fit. What water pressure do you have incoming to the house as whilst you’re cutting into cold supplies, a variable pressure reducer would also help somewhat and you can set it so you can retain a decent pressure. £100 should get you sorted and stop the problems across the house.

@Birk57 this isn’t an issue of trust, it is straight line contract assurance so it is relatively simple to sort. 1. check the company out, look at the history on companies house and the directors. Any significant change in the past 18 months would make me wary. 2. as @Bitpipe said - pay the deposit on credit card. Even if it’s £100, it covers you for default. It won’t help you recover consequential loss but it’s something. Make sure the contract for SIPs is in the same name and address as the card holder and the card address. 3. Consider the build choice carefully. Why SIPs..? What are you trying to achieve with that route as you will need to be in control as they need specific contractors, cranage, scaffold etc. First build with this and you’re taking on something that could need a lot of management. 4. You got planning yesterday ... with the best will in the world, unless you have a ground works contractor signed up and ready now, you won’t be out of the ground in 14 weeks, never mind ready for SIPs. Trades are maxed out, I would only push the button on a SIPs or frame order when everything is lined up and work is starting in the next 4 weeks as you will hit issues. Hope that helps.

Even with 2 course and paving it is measured at the house so unless the house is set a long way down (unlikely) then it’s fine. @Cheesy Crumpet your issue may be the 50% rule as that extension plus paving cannot be more than 50% of the area of the garden.

ST sounds expensive and possibly over what you can easily use. 16sqm of PV is roughly 12 panels or 3.6kW so can be had for about 80p/W 16sqm is approx 120 tubes at 58mm with a peak output of around 6.2kW so whilst it’s giving you a lot more heat it is going to need a lot more buffer / storage as in summer it’s got nowhere to go after that pool is warm.

So it looks like you’re barely at 300mm anyway with 4 bricks, assuming it’s the neighbour to the right complaining .?? And its measured next to the house. The Technical Guidance note shows height as : “Height” - references to height (for example, the heights of the eaves on a house extension) is the height measured from ground level. (Note, ground level is the surface of the ground immediately adjacent to the building in question, and would not include any addition laid on top of the ground such as decking. Where ground level is not uniform (for example if the ground is sloping), then the ground level is the highest part of the surface of the ground next to the building.)

Can do a cascade controller with the Finder relay and a pair of tank stats. Depending on the heat pump start signal (NV/230VAC/24VDC etc) then you may need two more relays rather than direct output but it’s all change of £100 stuff.

I’d be running a 2,000 litre buffer at max 45°C from the heat pumps and use it as a primary source to a 400 litre UVC. Then put the UVC immersions on an overnight tariff and as the primary dump load to 70°C for the PV. Buffer needs a pair of stats on it that kick one ASHP in at say 42°C then the next at 38°C. Simple switch over will mean that they get equal use and you’ll always have redundancy. Use something like a Finder 72.42 Priority relay. Solar coils and immersion dump loads can also go into the buffer and just put a differential controller so the buffer heats the main house UVC whenever it’s hotter by 5°C etc. Pair of 8kW ASHP will give you plenty of grunt but also allow you to have some redundancy if needed.

yes - they use the GPS clock signal. They are moving away from the old time signal as it’s not going to be continued so all the meters and the system use the same mechanism of UTC. The lead/lag in HH metering is about 2-3 seconds anyway so it’s swings and roundabouts to be honest.

+1 to Hwam and @Trw144 knows why .... absolute things of beauty and they work superbly. If you have budget then go for one - they are just beautifully engineered and a real quality piece of kit.

So if you’re going solar thermal for the pool as well you may want to run some sort of buffer as otherwise you’ll be having multiple heat exchangers.

Don’t use MDPE for the electric - if you need to put a duct in now, use grey or black 32mm poly waste pipe as it’s cheap and easy to lay and much better for the long bends at either end. Using blue MDPE is asking for issues and it’s not that big internally.

I would go for 3 heat pumps not 2... The one for the pool doesn’t need to be either an inverter driven one or posh - go for a pool pump and run it hard. Also look at using A2A in the pool room to keep the temperature normalised and also control humidity. The rest I would go for 2 smaller pumps running in tandem, and even consider using them with a pair of DHW tanks, gives you the option to boost your capacity only when you need it. GSHP is only worth it if you are going full MCS as the costs outweigh any benefits. How much PV are you installing ..??

Just on standards, the standard for PEX/Pert is 16/2 dia/wall. That’s Euro standard. nuHeat use 14mm .... non standard ...

Pipe doesn’t wear out. It fails due to damage, which is not in the warranty. PE-Xc is just their way of not saying PErt-Al-Pert or PEX-AL-PEX. It is 5 layer cross linked poly which is exactly what everyone else uses. They even state that here : Although the majority of UFH tube in the market is the same, many come with different warranties ranging from a couple of years to full lifetime warranties Their warranty is only 10 years according to the website too..?? Polypipe and ProWarm are 50 years, Wunda is 100 years ..... https://cdn.wundatrade.co.uk/wp-content/uploads/2019/03/P01-Pert-Al-Pert-Pipe-fact-sheet.pdf

The designs Wunda will do for you for free - and their tech support is at the end of the phone. There is only 12 months parts warranty on the NuHeat stuff. The only thing that goes wrong is the actuators or the pumps and they are change of £25/£100 respectively. If you send me the £950 I’ll give you a 5 year parts warranty on the moving parts too ... and I’ll probably still have £950 at the end of 5 years !!

Would be interested to see how they compare on price. Pumps are pumps, but from what I understand the NuHeat branded stats don’t talk to the heatmiser app or any of the core products so you have to go to them when anything fails.

where is it built ..? Can narrow down sometimes by location

Nothing wrong with plastic / ABS type stop valves, they are essentially what is in the bottom of every isolation chamber on every street. Just buy decent quality.

Do you mean steel needles to hold up an external wall ..? If so, you can use short lengths of RSJ - quicker and cheaper to buy and disposable at the end.

thats not enough for 2 showers ..