JamesP

I have 40mm Pavatherm fixed to timber frame, then membrane, batten, counter batten, Cedar cladding. Put some stainless steel rodent mesh top and bottom behind the cladding.

Having lived with an Ecodan for over a year now it has used just over 4000 kWh for both DHW and heating. This is for a very well insulated, air tight home with 5 adults. Never run out of hot water and the noise this particular unit makes is not an issue. It is sited outside next to the wall of the house. I originally planned for it to be sited 15 metres away but the suppliers said its not necessary. However in built up areas and in poorly insulated properties the results might be very different. And yes the RHI did influence the decision to proceed with an ASHP.

As noted above it does depend on your location, even from the same supplier the price varies by 30%+.

Thanks Ian, lowest rate from PFP is 16.84p and that's a variable summer rate. Fixed is 20.25p. Do prices fluctuate that much across the country from the same supplier? No detail, just current news reports which you are right to be sceptical of.

Please let me know where I can find a supplier for 12.5p/kWh. I have just changed supplier to find the rate of 18.97p/kWh who have just announced an increase of 11.7% on the 2nd August. The Government is looking at delaying the ban on gas boilers to 2040 due to soaring "net zero" cost.

Not an expert but having but my own house with an EPC of A I would not recommend an ASHP in your property. The electricity cost would be substantial and not sure it would be able to provide you with adequate heating. I would hang on to gas / lpg for as long as possible before being forced down the electric only route.

Similar build to yours, 275m2, 3G, MVHR etc and 8.5kW, Ecodan, 300l pre plumber cylinder. Works perfectly for our family of 5.

I have friends doing similar. Purchased 25 acres, which is probably the minimum, have farmed cows and pigs and now have planning to live in a temporary agricultural dwelling, a mobile home. They had to justify farming is the main source of income, it isn't. Employed a specialist planning consultant. Took 5 years before they moved on to the land. Will now try for permanent dwelling. Its all bit of game so think think long term.

Any ASHP will create some noise, bit of a hot topic here. We have a Mitsubishi Ecodan W85 and I would say it is a quiet unit to others I have heard running. I chose this unit for the pre plumbed cylinder and reputation from others on the Forum.

Can you explain what this means, I did use the dip switch last year and and it did cool without altering anything else. I have just installed plumbing and electrics for AC split system for upstairs bedrooms just before I closed off a ceiling.

@MortarThePoint If using Pert/Al pipe, try putting a soft bend in the middle of each pipe away from the floor, this should push the end of the loops down.

Noise concerned me about the ASHP (Ecodan) and the original plan was to site the unit behind the garage some 8 metres from the house. The installers suggested as close as possible to the UVC and it sits just outside the side door. It is not intrusive probably being in a rural location with no fixed objects in front of it, might be different in an urban garden bouncing off the neighbours fence. Looked at GSHP (slinky's) and just could not accept the disturbance of digging hundreds of metres of trenches. Insulation and airtightness first.

@Kesoolhe If you do fit PV, invest in a PV diverter if your cylinder has an immersion.

Hi Keith At first glance your costs seem about right. What EPC rating is your home? An ASHP is possibly more expensive to run than an equivalent efficient gas boiler due to the unit cost being 3 to 4 times the cost of gas. Is your home all electric? Can you separate out the ASHP units from the rest of the house and can you then break down DHW and heating. You might be running a fan heater in your garage.... I have been running a 8.5 Ecodan in a well insulated similar size home with MVHR and Solar PV accommodating 5 adults. This sunny April the PV generated more units than last July and August which all helps reduce the electricity consumption. For the month of July 2020 the ASHP used 140 units for DHW, no heating required and in January 2021, 242 for DHW and 421 for heating. Anyway it is all about reducing our consumption.

Inclined to agree with your comment. I enclose a picture of where I removed the waste pipes and then shoved a pressure hose down the vertical to clear the SSR. Wish I had paid a bit more attention to the design of the internals before filling. If and when emptied I will throughly clean out and take note of internal parts.