ASHP newbie

I can confirm that if you get GHG then it's taken off any RHI you may get later on ie the govt claws it back. Only a grant if you don't qualify for RHI .

Thank for all the info/advice. Problem solved as found that there were no seals at all in the join. Now got straight fitting in place and no leaks. Did use washing up liquid (and chamfer on the pipes etc etc). Sand/pea gravel is better than lumps of concrete that I dug up lots of and which caused a sag in the pipe resulting in another short horizontal section (now removed). I tend to do what I have seen builders do in the past on the assumption! that they know what they are doing. Whoever put in these waste pipes did NOT know what they were doing. Nice to be able to start filling in the trench. Still don't know just HOW washing liquid causes damage.... Shouldn't be so curious.....

I've had info on now on the Green Homes Grant - but they take it off any RHI payments so it just helps with some of the upfront costs. Can apply at end of this month. I'll see if I get anything. It is valid for ASHP etc.

Does anyone out there know exactly why every builders' merchant tells me not to use washing up liquid to lubricate 110mm pipe joins but every builder who's ever done any drainage work for me has always used washing up liquid (usually my own!). I assume it damages the seal - softens? or rots? it. Is that why when I disturbed a join in my pipe it started leaking (slightly)? Only one join leaks. The others are quite solid/tight, the leaky one is wobbly. Or is it more likely to be because the pipe has been cut too short to fit far enough in, making it wobbly/leaky? If the latter I'll need to add pipe and another join blah blah blah. Incidentally both ends are fixed so will need to fight with a slip coupler. Always terrified that I won't be able to put it all back together. I've been slowly digging up the waste system of my cottage because some idiot had put it in with an uphill slope at one point. Having sorted that I thought I ought to check the next section of the run. Not even a glimpse of sand or pea gravel anywhere, but lots of lumps of concrete, bricks etc.

My nearest neighbours are 1/4 mile away. And we are on a hill.

I've just asked for a bigger DHW tank to cope with my baths. And don't intend to change my rads unless I need to later on, tho was told one in my open plan living/kitchen area will need to be a triple. That's why I was looking at 50-55 degC for the rad water.

Would appreciate knowing whether I can take my time making up my mind or need to get on with it to get RHI. Am no longer talking with the 'pushy' company.

No I haven't read up on woodburners on this site but when the wood is free from the garden and very well seasoned ie several years, I think its env impact is acceptable. After all, it would just rot down otherwise (or go on a bonfire). Considering SCoP values I was looking at worst case scenario as I only have normal rads and am likely to need them reasonably hot. And I like my bath water pretty hot!

I've been told by one of the companies that are quoting for my ASHP that RHI won't be reduced until a certain quota of installations has been completed and that will take some time because of Covid delays. The other company has been pushing me to sign up asap, saying it will drop on 1st Oct.

Yes I do use the woodburner every evening in the winter, also sometimes Rayburn if I am going to be in all day. Guess this winter I'll be in most days - the way Covid is making us live. I am lucky I have loads of wood from sorting seriously overgrown hedgerows etc. and a few dead trees as well. Not had to buy logs yet - been here almost 6 years. My problem with my LPG savings is that they get wiped out by increased electricity consumption plus maintenance charges while under warranty (7 yrs). I think I've been quoted over-the-top maintenance, when I've searched the internet consensus seems to be once every couple of years - not every year.

Thanks, I did more looking up of stuff and got it sorted. Amazing, what one can find out in the internet :-) I've been quoted SCoP values of 3.51 at 55degC and 3.81 at 50degC. Seemed reasonable.

Since I asked the price from one of the companies quoting for ASHP. That included installation. What should I expect it to be?

Thanks for that! I've stuck it into my spreadsheet and bearing in mind that it's all approximate I should make some savings - at least I now feel more confident that my electricity bills shouldn't end up higher than my current bills +LPG.

I've worked out I use about 1kWh a day in the summer. It's actually 1073kWh a year. Whatever, it's low and I want to keep it that way. I did suggest a smart switch to the installers and they said to use the ASHP in summer as it's more efficient. I'd still like to dump any surplus electricity into the tank but it's another £500 or so. Maybe later. My projected savings are pretty low as my usage is so low, hence the worry that any savings will be gobbled up by the extra electricity needed to run the ASHP for hot water and an immersion for hop water top ups. I do like a hot bath :-) Do you know how much elec your ASHP uses to heat your water each week say? For how many people?

The SCoP is 3.81 at 50degC. Don't know the CoP. How does it differ from the SCoP? Also heard that SPF matters but don't know what it is. More info re the house follows (copied from "Introduce yourself" sub-forum): The house is reasonably insulated for its age - roof insulated, all north-facing walls insulated internally, other walls maybe half insulated where appropriate. EPC D with solar PV, since it was done have added oak frame extension where double glazing manages to lose more heat than I am happy with but it is to 2015 regs. All windows and doors double glazed. About half of solid floor area also insulated. Most insulation is 4" of Kingspan as far as I remember. I've had the ASHP sizing done for 11.4kW system with heat loss factor 62 w/sq.m. floor area 148m2 (should be 167m2 - ignores hallway etc) heating energy req't 16,787kWh and hot water req't 2,606kWh. Tried doing the sums but got bogged down so thought I'd try see if some knows because they been there/done that. Also been thinking of noise levels (sound power 66dBA) as the unit will be below a first floor bedroom window (spare room). And what would have happened during The Beast from the East as the unit will face East.