I bought a Heat Pump

Reed_Richards

I live in a village without mains gas and inherited an external oil boiler when we bought our bungalow in 2018.  This is a timber-framed property built in 1980 and the central heating pipes that fed the radiators had been buried just below the surface of the concrete floors without any protection against corrosion.  Replacing the tiles on our kitchen floor revealed that these pipes looked like they were indeed suffering some corrosion so we decided to move all the central heating pipes to the loft.  At about the same time we found a small crack in our oil tank.  Our oil boiler had been installed in 2012 and I had planned to keep it running for a few more years but the need to move the heating pipes and replace the oil tank caused me to change my mind and look at heat pumps.  I looked at both Ground Source and Air Source heat pumps but the cost of drilling the necessary bore holes put me off Ground Source.  I live in the far north of England and I struggled a bit to find heat pump installers.  I got two quotes from different companies with large teams of fitters but eventually settled on a small company based about an hour away who could give me a quote for the entire job.  They came and made a heat loss survey which concluded that I needed a 12 KW heat pump, to replace all but three of my existing standard radiators and to add two additional radiators.  Even then I elected to tolerate being short of heat in two rooms.  The heat pump was installed at the beginning of December 2020 so it has been in use for about 2 months now.  I intend to post on how it is doing and I am happy to try to answer questions.        

Reed_Richards

The worst aspect of the installation was that it turned-out I would have to replace my relatively new hot water cylinder.  Heat pumps require that the coil inside the cylinder has a much larger surface area than normal so that the cylinder can be reheated quickly with the lower water temperature provided by the heat pump.  To make matters worse, the replacement cylinder was less-well-insulated than the old one - which is now sitting at the back of my garage whilst I ponder what to do with it.  There is now also a pump inside my airing cupboard where the cylinder is sited which is quite noisy in the adjoining room.  Previously my central heating pump was inside the oil boiler outside the house, which made for silent running of the central heating.  It's not silent anymore.  

shinytop

Very interested in your experience as we are also without mains gas.   I suppose the obvious first question is how much was the installation and for what?

tacpot12

It will be very interesting to hear about your experience. I too would like to know what system you bought. It might also be useful for someone to know what cylinder you bought. 

Was there a reason why you didn't go for ASHP with an integrated cylinder?

Reed_Richards

Installation cost is a bit awkward because a normal installation would get you a heat pump, hot water cylinder and new radiators and I wanted new pipework to all the radiators as well.  The cheapest (provisional) quote I got was £15,500 which would have got me a Grant 17 kW heat pump, cylinder and 10 new radiators.  But they could only guess at what the extra pipework would cost and did not include that in the quote.  One of the problems is that sizing the heat pump and the radiators requires a full heat loss calculation and you don't normally get that done until you sign-up.
The quote I went for was just under £17,000 for a LG 12 kW heat pump, 300 l hot water cylinder and 9 new radiators (as it turned out one was adequately sized) plus all the new pipework.  This quote also included splitting the house into two heating zones and the company did the full heat loss calculation before giving me the quote so it was a much firmer quote than the rest.
Obviously this is a huge sum of money compared to the cost of a new oil boiler and a new oil tank, which was the alternative of least resistance.  But I hope to claw-back a fair bit of this cost through the RHI (Renewable Heat Incentive) payments.  And there are some big wind turbines a few miles from my house which, hopefully, are what provides me with the bulk of my electricity.

Pile_o_stone

This will be an interesting thread to keep a watch on as I'm sure lots of people will be moving to ASHP/GSHP over the next few years and would like to see real-world running cost comparisons. My first question though is why don't you have  have heating in two rooms?

Reed_Richards

The cylinder came from a company called "Telford Copper and Stainless Cylinders Limited".  I think they supplied my installers with the heat pump together with the cylinder as a package.  It's huge as it has a 300 litre hot water capacity and also a buffer tank integrated into the base.  I presume this is what you mean by "integrated cylinder" @tacpot12?   My version came pre-plumbed.     

Reed_Richards

During the last 5 days of cold weather the average power consumption by my heat pump has been 2.5 kW.  That doesn't seem too bad to heat the entire house but I was paying an average of £920 per year for oil and in the last two months I have spent over £400 on electricity for the heat pump so I am not very confident I will be able to match my previous fuel costs.  

Reed_Richards

Pile_o_stone said:

My first question though is why don't you have  have heating in two rooms?

All rooms are heated; you must have misunderstood something I wrote.  The large lounge/dining area now has 4 radiators (it used to be 3) and we added a radiator to supplement the existing heated towel rail in the main bathroom.  All other rooms are heated by a single radiator.  The interior hallway is unheated.  

michaels

Reed_Richards said:

During the last 5 days of cold weather the average power consumption by my heat pump has been 2.5 kW.  That doesn't seem too bad to heat the entire house but I was paying an average of £920 per year for oil and in the last two months I have spent over £400 on electricity for the heat pump so I am not very confident I will be able to match my previous fuel costs.  

Are you comparing like with like in terms of temperature in the house?  Obviously it has been a particularly hard test of heat pumps as at least where we are the average temps have bene below the monthly norms and heat pumps don't like the cold.

Pile_o_stone

Reed_Richards said:

Pile_o_stone said:

My first question though is why don't you have  have heating in two rooms?

All rooms are heated; you must have misunderstood something I wrote.  The large lounge/dining area now has 4 radiators (it used to be 3) and we added a radiator to supplement the existing heated towel rail in the main bathroom.  All other rooms are heated by a single radiator.  The interior hallway is unheated.  

Yes, sorry I thought your comment "Even then I elected to tolerate being short of heat in two rooms." meant that you didn't have heat in those rooms, rather than having some heat in there.