joe90

Ask @Nickfromwales about hep 2o longevity.

@JSHarris, just bumping this, your thoughts? @JSHarris as your ASHP is very similar to mine, I have been going through all the settings again now I am beginning to understand how it works. Parameter 106 is (1) external heat source or (2) defrost, and the default setting is external heat source (1). Surely with no external heat source installed this should be set as 2?.

@Stones, What temp do you heat your DHW.

Just spoke to my neighbour who has an ASHP (he’s a plumber) and he runs his DHW at 48’ and it very rarely defrosts so that looks good for our location!?. Yes @JSHarris, I will run it and see how it settles down, measure consumption and decide in the future if changes are needed. How do people measure their water temp, I tried a mouth thermometer from when the kids were young but when it gets above 40 it has a fit!!!

Ah, makes sense. Back to my little fan heater then?. Whilst thinking this through I was also thinking of E7 or E10 to reduce running costs but as these are mostly night times, temps will be lower so defrosting may be more of a problem, so will the savings be worth the defrosting (when). Gosh I wish I had mains gas! (Actually apart from the programming I am enjoying the challenge to get it right). Using the little grey cells (what’s left ).

If you fill it in, it will save you a fortune in skips ? we had to dispose of 150 tons of clay.£££££££. Our current problem in our new build is Storing veg somewhere cool (we drink the wine too fast to store it!).

@jack I found a good blowtorch over the OSB for a while is good as long as the OSB is not sodden, don’t scorch it but those torches they use to stick hot felt down are good ( I used to rent one) .https://www.hirestation.co.uk/tool-hire/Plumbing/Blow-Torch-Hire/140040/

@JSHarris as your ASHP is very similar to mine, I have been going through all the settings again now I am beginning to understand how it works. Parameter 106 is (1) external heat source or (2) defrost, and the default setting is external heat source (1). Surely with no external heat source installed this should be set as 2?. I have said before (not wishing to go on about it ?) that I would have thought that the heat pump could recognise when it’s about to defrost and simply stop itself (max water temp achieved without defrosting). I wonder if when the external heat source is activated the pump stops till the icing has stopped, if so then if i select external heat source but don’t instal one I will achieve my goal?

As @ProDave says about the Willis heater, it occurred to me that my buffer tank that is right next to the ASHP might act the same, as long as the temp in the tank does not go below the UFH temp then the house temp will not suffer!!

Yup, even house location makes a big difference, it’s down to trial and error till we achieve what suits best.

Yup, my missus asked me how to “work it” and I had to say “I need to work it out for myself first!”. Regarding a passive house needing “special systems” I think I understand that Jeremy has done that with simple controls. I am not worried about temps varying a bit, I know that response times will be long with what we have but like @JSHarris I am sure we will get there (with a lot of help from this forum ?).

I take my hat off to @TerryE and the like who can do this stuff, I have trouble programming the tv remote ?. The older I get the more I become a Luddite.

I little fan heater pointed at the fins????.

I did wonder if a resistance heater near the ice would be a cheaper way to defrost the ASHP (I am sure I saw parameter 106, external heat source or defrost).

I am not sure I want our house at a constant temp!. I am only just getting my heating going and learning how it works/suits us. With the solar gain we get during the day (mostly) and being active. I am sure we need no heating but when tired in the evening we need a warmer envoironment. The same goes for first thing in the morning, nothing worse than a cold bathroom (reason for electric towel radiator and UFH) or cold kitchen for breakfast. I was pleased/relieved when @JSHarris found a simple room stat was better than his complicated programming etc (as I have no idea how to do that). ?

I too have one of those as a plan B as I thought it would use less lecky than an immersion, plus the lower the DHW temp that’s stored the less the losses (although unlike @JSHarris I have found our tank looses very little heat, in fact er indoors complained that the airing cupboard was the same temp as the rest of the house?)

Thanks mate, I am chuffed like you after our problems, see my other new thread!!!!

After so much help here about the farce getting my ASHP to work, I thought I would start a new thread to discuss the ways it can interact with UFH and DHW. Our house is in a windy location and its been mentioned in other threads that this leads to a greater house heating requirement even at passiv levels of insulation. I have a 90litre buffer tank heated by the ASHP, the UFH loops are fed from this buffer tank via pump and manifold. If I get the ASHP to heat the buffer every time the room stat calls for heat then the UFH will take a long time to heat the house (no idea how long). If however the buffer (in winter) is permenantly heated to say 35’ and the room stat controls the UFH manifold pump the reaction time will be shorter. I have found the tanks I have are very well insulated and loose very little heat, plus any losses heat the house anyway as background heat. With regard DHW, I don’t want the ASHP to defrost so could limit the temp from the ASHP (by tank stat) to say 40’. As we want DHW at about 47’ the changeover contact on the tank stat when it turns the ASHP off could switch the immersion on which will turn itself off when 47’ is reached. (just read the stat info and it appears to switch 10A! a 3Kw immersion draws 12.5 A so I will need a relay I guess?). I would welcome any thoughts on this plan.

I now have 20, 20 hindsight , I also have ordered a computherm room stat (that @JSHarris recommended as I can’t be arsed to wire in a relay to deal with the Wunda stat that blew my main ASHP board ?

Right, drained it down and took the diverter valve off and confirmed that in parked mode water flows from AB to B. Which should be heating, when powered up water flows from AB to A (DHW). This is as per @Gav_P pic above but not as the drawing I got with the valve. NOTE, I noticed that when using the manual override on the valve it only opens the valve halfway like a mid position valve!!! This must be for drain down only and not to manually operate the valve, this is why when trying the valve I was confused as both pipes got hot, it can only be tested by electrical energising.

Yes but it’s your roof, not his and your money !

Yes, but, this is my back up for our bedroom if the weather is very cold for the odd couple of weeks in the winter. I did not want to go to the expense and work of UFH upstairs Just in case it got that cold occasionally. I bought a slimline 500watt heater that lives In a wardrobe that I can plug In fir an hour or so. I have wired for a post heater in the MVHR but not sure of its effectiveness.

Thats little to pay for a GOOD QS regarding what you are spending, as a project manager and builder in a previous life I didn’t need one but I found myself having to justify “spend” to my wife who didn’t understand building costs. I also had a brilliant main contractor so consider myself very lucky after reading stories on here.

@JSHarris is right about local weather conditions, we are the opposite to him, we have almost constant SW winds from the coast and I believe it impacts on our heat requirement .we are very near passive hous insulation and airtightness but ASHP and UFH are needed to provide affordable heating and DHW as we have no mains gas.

No, definitely not, I don’t know how he could call himself a roofer for 25years. Frankly I would not pay him a penny.