Posted by: @sand

The upstairs is always set at 19 the downstairs is set to 21 so just wanted to set back downstairs to 19 overnight. We were told the wireless controller just worked the rads upstairs but I can try it downstairs, thanks.

Hi Sand,

If that does not work then just program your downstairs thermostats to set the temperature at 19C overnight, which should reduce your energy consumption.

@andygo beware the wood burner route ideal for back up but we currently use ours as the main source and our bill for kiln dried wood is £1400 pa. We are waiting for our ASHP to go in next month to replace our old LPG boiler and to get used to the new system i have for the last 6 weeks turned the rad out flow down to about 38 degrees and run the system for 19 hrs a day  the temp is fairly cool in the house but the drop in LPG usage has been remarkable  however with losing 1700 pa LPG costs and reducing our wood bill to about 600pa means i have a lot ofKWhrs to play with. Incidentally we are installing 2x 7KWh valiant s and avoiding all forms of zoning and TLVs just relying on the unit and weather compensation running the system 24th a day

£1400 on logs seems very high! I run a 13 KW logburner and use 96 boxes of Eco Fire Hot rods a year  which is basically oak saw dust compressed.  A ton cots less than £300.  I then burn dried logs in the evenings when sitting in the room to enjoy the double burning flames.  Its saved the day now that my ASHP is on a high tariff.

Ive been running my 8kwh burner for 14 years now it runs 24/7 from sept to may and we het through 4/5 pallets of the verdo or similar heat logs  until the last 2 years we simply turned of our central heating cos up here were not softee southerners! But since retiring we have put the heating on as well. Our problem is we are quite exposed, reasonably well insulated with d or t glazing on an old random rubble cottage which has been 50% extended over the years. The CH rads and piping is up to 38 years old and micro bore so that is all being ripped out and renewed with ASHP compatible rads and piping incidentally our living room where the log burner is has no radiators but is the largest room and we keep the door open to the back of the house hence probably our large burn. My reason for swinging to ASHP is primarily to make the EPC up to C bearing in mind the mad drive by both the Scottish Govt and the UK Govt to apparently enforce energy efficiency by seemingly directing the mortgage lenders thus making our property harder to sell in a few years time. I would add that for the last 20 yrs i have been heavily involved in property management and working as part of our associations policy committee liaising with the scottish govt and i am in the lucky position to be able to afford the rather large outlay to completely rip out my system. It is going to be a very interesting 12 months to see how we go!

@mikefitz, do you have a link to where you buy these from? 

@editor https://www.uk-timber.co.uk/ecofire-hotrod-briquettes/661-boxed-ecofire-hotrods-pallet.html

@mikefitz @sapper117

thanks for that, the briquettes look a good option. The project I have been working on has a woodburner, & fortunately has had a good supply of Oak from a very large tree fallen on the access road some years ago, now down to the last of it (plus a heap of large knotty impossible to split chunks).   I have no idea what folk are paying for air dried logs these days. 

The house is also a random rubble affair, not very well insulated except the loft, mostly concrete floors & v hard to heat. Miles from a gas supply, so there are economy 7 storage heaters 😱 Which actually seem to work fine as long as the weather isn't below freezing for very long periods. They are never run in boost mode - you might as well burn £20 notes in the stove... The woodburner is vital then. Being near a well wooded area is handy but few people have that benefit. 

The briquettes come in carboard boxes which are easy to handle, clean and stack well.  They do not take to getting wet however!

I have started looking at what it would take insall a heat pump to replace our gas boiler when it eventually dies, and I am grateful that I found this site as a good source of info and experience.

The latest problem that I have come up against is the capacity of the mains power supply.  I was looking at an 18kW Daikin Altherma 3 H HT (similar to Julian's system), which would need 75 amps of the 100 amps that my single phase supply provides.  Thinking ahead, our next car will be electric, but with a 7kW charger (29 amps) we will blow the 100 amp supply fuse if the car is charging at the same time as the heat pump is operating.  

I just had UK Power networks come round to quote for a supply upgrade to 3 phase, for which they would charge approx £10k, which would kill the project financially.

Has anyone else on the forum got some clever tech which stops the car from charging when the heat pump is running, and vice versa?  In practice this should work fine, as the car can charge overnight when we wouldn't be heating the house, but I would like something failsafe rather than having to remember every time to schedule the car.

@timh hi, we have a 13kw system newly installed and an electric car but currently charge that on a 3 pin socket. Northern electric told us we needed an upgrade to our supply and bigger fuse capacity (I think , will check with my husband the terminology) they did this for £150 , very easy and quick! Will find out more from the invoice if that helps? 

Posted by: @timh

I have started looking at what it would take insall a heat pump to replace our gas boiler when it eventually dies, and I am grateful that I found this site as a good source of info and experience.

The latest problem that I have come up against is the capacity of the mains power supply.  I was looking at an 18kW Daikin Altherma 3 H HT (similar to Julian's system), which would need 75 amps of the 100 amps that my single phase supply provides.  Thinking ahead, our next car will be electric, but with a 7kW charger (29 amps) we will blow the 100 amp supply fuse if the car is charging at the same time as the heat pump is operating.  

I just had UK Power networks come round to quote for a supply upgrade to 3 phase, for which they would charge approx £10k, which would kill the project financially.

Has anyone else on the forum got some clever tech which stops the car from charging when the heat pump is running, and vice versa?  In practice this should work fine, as the car can charge overnight when we wouldn't be heating the house, but I would like something failsafe rather than having to remember every time to schedule the car.

@timh

How is the 75A requirement derived? I wouldn’t have expected this, more like say 25A under load for 6kW of electrical power, COP of 3. A quick look at the Daikin specifications gives a supply fuse requirement of 32A for the outdoor unit, 20A for the indoor unit. It looks like 18kW divided by 240V, which gives 75A. I’m not sure that is correct.

@rusty that is a good point.  A 7kW car charger will use 7kW, but if the heat pump is 300% efficient, then if the output is 18kW, the input would only need to be 6kW, which makes a big difference.  Thank you!