PeterW

Boiler circuit pressure is slightly low, but that won’t affect the showers. More likely it is the shower itself - thermostatic caps can fail after a while and this is what happens.

The law changed a few years ago on lateral drains, and now every one that serves more than one dwelling becomes the property of the sewage provider from the boundary of the first property on the run (ie between first and second connections). @Jason L what number connection are you..? You will need to discuss with your neighbours about changing this as it could have impacts on them whilst the work is done - even temporary - and the more there are, the harder and more expensive it becomes as it has to be done quickly.

I think the tank controls are not right - wonder if it’s wired up incorrectly. I would start by upping the thermostats to 65°C when they should cut in. Also I have vague (possibly wrong..?) memories about this TS having a couple of funky TMVs in it somewhere to balance off the flows ..?? Or was that someone else’s ..??

Ok - even so, the boiler should be operating at full tilt for 7 hours a day, getting through 20kg of pellets to give you the heat you need. How many is it burning a day ..? 30kg..?? So something is out of whack as it is using 50% more pellets but not giving you the heat. Have they checked the combustion efficiency ..?? Is it burning clean ..?

Yep - couple of bits every other bay both sides of the roof. Your vents aren’t that big, needs a low flow not a gale

Decent fuel and good fuel oil mixing is the key with anything 2 stroke. I only use super unleaded with Stihl single shot oil, never have an issue with chainsaws or disk cutters. Tried that Aspen pre-mix and binned it as it was awful !!

No, just no... Drink the vodka and go to bed. And forget about a tank under the floor..! How would you drain it down for starters ..??!!

I’ve got a 9” grinder with a diamond disk and it’s great for small stuff like blocks and bricks. Feels light in the hand and it will cut most things. Downside is the cable being dragged around ! I’ve had a play with the new Makita LXT 9” one that has 2 batteries but I can’t see how this will stand up against either petrol or a mains one.

Ok have you got the page that shows the expected kWh/m/yr from that one as it’s very different in its score to the As Built. The as built shows an A rated house with pellets - that is a very odd thing as your 105kW/m2/yr is quite high.

Which came first ..? EPC or the RHI calcs..?? Installer also needs to show how he came up with the design too.

Thanks @recoveringbuilder, there are some discrepancies in those numbers, but lets go with the lower from the RHI of 15,787kWh per annum Based on a reasonable spread and some use of Met Office data. I've got the following : January February March April May June July August September October November December Heat Input 2263 2044 2010 1456 998 354 113 239 721 1504 1823 2263 DHW kWh 214.8 194.0 214.8 207.9 214.8 207.9 214.8 214.8 207.9 214.8 207.9 214.8 Heating kWh 2477.9 2238.1 2224.9 1663.4 1212.8 561.6 327.3 453.8 928.9 1718.8 2030.7 2477.9 Per Day/avg kWh 79.9 79.9 71.8 55.4 39.1 18.7 10.6 14.6 31.0 55.4 67.7 79.9 Hours @ 12.2kW 6.55 6.55 5.88 4.54 3.21 1.53 0.87 1.20 2.54 4.54 5.55 6.55 You'll see the bottom line shows the burn time for the boiler in hours - that is a big number in November - March, and by the sounds of it the boiler isn't running flat out so needs to be longer than that in reality. Also, the EPC shows a Primary Energy of 105kWh/m2/year for 269m2 but that would equate to 28,245kWh a year which is nearly double what the RHI calculation shows. I would hope someone somewhere has made an error on that number, but... if the RHI number is wrong, it would give even more support to the claim that the calculations are wrong and the boiler is much too small. In fact, if the RHI calculation is that far different to the SAP score I would suggest you may be in the negligence territory and insurers would possibly get involved at this point. Possibly not what you want to hear, but it may help clarify a few things !

Ok so total kWh for the year is different. Have you got your SAP calculations ..?

Ahh you are alive ! 10mm Plug Cutter is what you need - fits in the drill and cuts a nice plug out of a bit of timber. If it won't release from the source wood just flick it out with a chisel. Glue it in, leave the glue to go off then cut flush with a sharp chisel. https://www.amazon.co.uk/Faithfull-5023969227566-Plug-Cutter-No-10 You can buy them in sets too - I use them a lot and the erbauer ones from Screwfix with the countersink and the matching cutter are brilliant for the price https://www.screwfix.com/p/erbauer-plug-cutter-countersink-set-4-pieces/6418V Nice little video to show you how

Short lengths of overflow pipe work just as well and much cheaper !

@Roz Turning it to the left as you look at it makes it warmer. The rectangles get bigger on the head the warmer it is ..!

Can you not use the room to house something like the hot water cylinder ..? That will create enough warmth. MVHR needs an undercut of 10mm on the doors so you will get air flow. Are you installing towel rads in the en-suites..? Electric or water ..?

I would integrate heat and smoke into the alarm but not into the systems such as NEST. They are designed to save your life, relying on something that in its own words was “designed to look good as smoke alarms are ugly” is starting from the wrong end of the requirements ... A decent smoke and fire alarm can be integrated into an alarm system - I’m assuming (hoping given the price..!) that Verisure can do this too. I think about 75% of the tech installed in new houses doesn’t get used. How often do people walk into the lounge and go “Hey Mabel (other voice controlled systems are available), put the lights to romantic and play Barry White...” This sort of thing takes ages to set up and to be honest I expect that the frustration is when you have left something in the lounge, you can’t just walk in and press a single button to turn one light on, then pick up said item and walk out. If I had to programme a scene to allow me to do this then it would rapidly become pointless. Depending on your heat method (UFH..?) then smart heating becomes reasonably irrelevant as your ability to influence heat input in any sort of real-time impact is negligible. Multi room systems only work when the rooms are isolated - leave a door open and you have just messed with the controls ..! If you want to trigger something such as a post heater in MVHR then an £20 Shelly will do this for you - you don’t need some amazing bespoke app with a complex control system. I would really look at your use cases for the tech and then decide what you really need - I think you will be surprised at how much isn’t really a need, it’s a want and it will become very expensive.

Chances are the oil combi was 25/27kW and you’ve replaced it with something a third of the size. That means any old ideas about the programming for heating go out of the window. Also, your losses as @SteamyTea says need to be known as at -5°C you may be losing more than you can inject. A basic system (assuming standard rads) putting 50W/m2 into the building needs 8.45kW - it could be your losses are nearly equal that so your 9Kw ASHO will struggle to maintain the desired heating levels unless it is on for much longer periods. There is a common misconception that ASHP reduce the amount of heat energy needed for a house - people install them, try and run them on the same programmed times as their old boilers that were 3 times the size. Basic physics of thermodynamics says that cannot work.

I’d be more concerned the corner posts are sat on wooden wedges and appear not to be bolted to the floor correctly ..! Have they had grout poured under them now ..??

Biggest hole saw you can find and cut two or three holes with it. Then just glue a bit of batten on the back, smear of filler round the edges when you put it back and job done.

Welcome if you’re planning a house that is airtight and well insulated, don’t bother with RHI as it will never pay back the “MCS Premium” that it will cost to get it installed. Beware you can’t just “do a course” to become MCS accredited and there is significant cost to the person who wants to become a registered installer. This isn’t just about becoming certified on an ASHP install, there is significantly more to it. I would focus on getting the heat demand down and then install the smallest ASHP required and leave it at that. Depending on location you can get heat pumps that are treated for coastal regions which may pay dividends as the heat exchanger will last much longer.

Order about 50 concrete coursing bricks, tell the brickies you want a decent bond on the blocks then go put the kettle on ... when ordering, it’s 10 blocks to the square metre, measured through for wastage. That means you measure height and width and ignore the door and window openings (unless they are huge) and just multiple the square meterage by 10. There is no need to have the internal and external perps aligned, just keep the beds aligned and it will be fine.

My 2 channel controllers have holiday mode built in ... Can’t see the point of an app, and if it’s the Heatmiser one I would read the app reviews first ...

So I assume this is the usual set up with a TS and the oil boiler in that there is a very simple programme (ie 6am - midnight) for the oil boiler to heat the TS, and the heating just pulls from the TS as and when it needs it. There is no boiler interlock per se, and it’s fairly simple as long as no-one runs the heating outside of the boiler times. To do it “correctly” you would need to interlock the lot - probably needs a 4 channel timer too, but not the end of the world to just ensure that the boiler time clock runs for longer than the CH pumps.

I wouldn’t do it. If the client insists then it would need them to sign a disclaimer that any warranty was null and void and you were not liable for the floor or any other consequential damage caused by a failure of the flooring. This is the sort of situation that ends up getting nasty when it invariably goes wrong.