People Saying Heat Pumps are Rubbish - Are They?

smallblueplanet

We needed a new boiler as our old oil boiler and plastic tank were reaching their 'end of life' stage. I got a quote from local companies and from Octopus. We decided, on Octopus as it was 'competitive' and their customer service had good reports, and that an ASHP was the way to go. We don't have solar/batteries but it would be cheaper if we did. It works in a different way to oil/gas heating, it's a steep learning curve, but is just as warm in the house.
However the 'famous' Octopus customer service hasn't been that apparent and our relatively straightforward install was/is (still happening four weeks after start) poor quality, which I'm still in discussions about.
We have an thermostatic mixer shower and was worried about water pressure difference, so although they couldn't 'do' cold balancing they fitted a PRV to make sure the shower worked as normal. We did get a 250l tank installed though instead of the 180l that MCS considered big enough.
Would I do it again, yes but maybe not with Octopus, it depends how it finally turns out. FWIW the majority of posts I've seen are from happy heat pump owners many having had Octopus installers.

shinytop

Reed_Richards said:

QrizB said:

Paging @Reed_Richards and @matt_drummer and @michaels and @Spies and @NedS and @matelodave and all the others - sorry to those I haven't named!

@shinytop springs to mind as one of the earlier adopters.  

Thanks for the name check; I haven't posted much lately though.  My view is that ASHPs are a bit like EVs.  All things considered they can work very well but are a bit harder to live with and a bit more expensive than the ff equivalent. I'm glad I got my ASHP and it works very well for us.

I'm moving house soon so will be back to gas CH for a while at least.  

Spoonie_Turtle

We have a heat pump but it replaced old storage heaters (that we didn't know how to use properly), decided by the housing association.  So we've nothing to compare it to other than a freezing house and inadequate expensive plug-in heaters.  For the first time in my life I'm warm!  The first winter since the heat pump was installed, I finally understood how not everyone was constantly miserable in the cold weather!  And I still marvel at it, 5½ years later.

I don't think ours is set up for optimal usage but it keeps us comfy without using an excessive amount of energy - apart from the vampire load (30-70kWh in a month for non-existent 'heating') which we think the only way to get rid of is to turn the whole system off when we don't need heating, but for multiple different reasons none of us are willing to risk it.

The overall COP for ours over the year is ~2.8-2.9*, but we don't have it running overnight as there's no setback temperature and it keeping kicking in to get back up to 18℃ in the wee hours of the morning was very annoying. 

[*I haven't actually put the data into the spreadsheet for all of last year so I've not calculated, but someone turned it up from 18℃ to 19℃ and the usage figures don't look much different so the COP may actually be slightly higher now.  I'll have to do that at some point, and try to remember to come back to this.]

You'd hope people choosing to get a heat pump themselves would be able to choose a model without a vampire load and with a setback option, both of which would likely make it more efficient to run than ours.

Spies

My heatpump replaced a perfectly good gas combi boiler. 

I've always struggled to heat the house to a temperature that felt comfortable, last November the temperature swing was from 16c to (just) 20c. I ran the boiler at the lowest flow temperature that was practical (45-55c) but it always felt like a waste of money for the (little) benefit it brought, there was always a cold draught in the Livingroom (which happens to be double height).

Since getting the heatpump it's been way more comfortable, I spent the first few weeks playing with the weather curve and trying to decide whether I wanted to run full weather compensation or have the thermostat influence, I finally settled in the latter. 

I find heatpumps - like EVs, do require some knowledge about the tech to understand how to get the best out of it but it definately works when set up correctly, my fear is a lot of heatpump installers will adopt the set and forget methodology which will end up with the end user paying way more than they should and poo pooing it over gas. 

For context vs last November, the house was way more pleasant this year and I have temperature data to back it up so it's not just a placebo, and overall, I used (monetary wise) a fraction more than last November but it actually feels worth it as I'm getting a very pleasant heat in the house without the draughts caused by the rapid heating from the gas boiler.

My weather curve is quite high compared to everyone else but it's needed else the temperature doesn't climb at all when it's colder, I use 46@-5c and 32@20c with a DT of 6 a modulation of 4 and an overshoot of 2 

Bendo

matt_drummer said:

Mine works OK

SCOP of 5.0 since February 2024 for heating and DHW

House is 23c downstairs and 21c upstairs, so warm enough for most people.

Worst day so far, average -1c, used 19kWh of electricity.

I pay 7p for electricity as I have large battery storage so my cost of heating and DHW is 1.4p per kWh (ignoring battery charging and discharging losses, maybe 1.8p per kWh including them)

If I was on a standard tariff then my cost would be about 5p per kWh, so the same or less than the price of gas.

Mine is nothing special, an Octopus install, nothing fancy and not a high end heat pump, I have a Daikin.

I do have large radiators though.

Didn't you have to chase them to replace your original HP because it was too large and didn't operate efficiently?  In that respect, you could argue there is something special about your install as just people wouldn't have realised and had it replaced.

Apologies if I am mixing you up with someone else.

Reed_Richards

My impression is that the most special feature of @matt_drummer's installation is the amount of time and effort he has devoted towards optimising it.  Was the original incarnation inefficient or just not as superbly efficient as what was finally achieved?   

matt_drummer

Bendo said:

matt_drummer said:

Mine works OK

SCOP of 5.0 since February 2024 for heating and DHW

House is 23c downstairs and 21c upstairs, so warm enough for most people.

Worst day so far, average -1c, used 19kWh of electricity.

I pay 7p for electricity as I have large battery storage so my cost of heating and DHW is 1.4p per kWh (ignoring battery charging and discharging losses, maybe 1.8p per kWh including them)

If I was on a standard tariff then my cost would be about 5p per kWh, so the same or less than the price of gas.

Mine is nothing special, an Octopus install, nothing fancy and not a high end heat pump, I have a Daikin.

I do have large radiators though.

Didn't you have to chase them to replace your original HP because it was too large and didn't operate efficiently?  In that respect, you could argue there is something special about your install as just people wouldn't have realised and had it replaced.

Apologies if I am mixing you up with someone else.

You are not mistaken.

You can argue whatever you want.

There isn't anything special about it though. Even the heat pump I have now is twice the size it needs to be.

However, in the context of the original question, both of my heat pumps managed to heat my house sufficiently.

Hoenir

matt_drummer said:

Hoenir said:

 born_again said:

TractorFactor said:

I think most of the people I've spoken to have always read "something" about heat pumps being a bit rubbish for heating homes and having showers.

But I rarely see this from people who have them installed, where the general view seems to be fairly positive.

I understand it's a bit of a learning curve coming from a gas boiler to a heat pump set up.

Our boiler has a flow temperature of 55°C anyway and that seems good enough for our radiators and showers.
The house isn't too bad with insulation but I'll be adding more to the loft, so that will be 200mm - 300mm of insulation up there.

For people who have had them installed, are they okay? Do they really keep your home nice and warm like a gas boiler would?

Sounds just like the EV arguments. 

Like EV's it's the upfront cost that's the real issue. 

The only issue is that most ev's aren't that old yet.

Second hand Tesla's will be out of people's price range insurance wise. Personally I'd never buy a Peugeot of any kind. The initial depreciation on your wife's model speaks volumes. As to why demand will remain constrained. Leasing companies are going to have to factor this in. Must be taking a sizable hit on existing contracted vehicles. 

Hoenir

Reed_Richards said:

I have had a heat pump for 4 years now; before that I had an oil boiler.  My heat pump keeps my house just as comfortably warm as before, but I had to replace nearly all my radiators with ones having a larger surface area as part of the installation.  Running costs have been a bit less than they were for my oil boiler but it's not made a huge difference because electricity costs a lot more per kWh than oil or gas.

What was the total cost of the installation can I ask? 

Reed_Richards

Hoenir said:

Reed_Richards said:

I have had a heat pump for 4 years now; before that I had an oil boiler.  My heat pump keeps my house just as comfortably warm as before, but I had to replace nearly all my radiators with ones having a larger surface area as part of the installation.  Running costs have been a bit less than they were for my oil boiler but it's not made a huge difference because electricity costs a lot more per kWh than oil or gas.

What was the total cost of the installation can I ask? 

My bungalow, built in 1980, had the copper pipes that fed all the radiators buried just below the surface of the screed and unprotected.  Since this is a recipe for corrosion and eventual leaks in the long term, we took the opportunity to put new pipes in the loft to replace the existing ones.  But this made the installation need much more time and effort; it was almost like installing a complete new heating system.  So unless you want to do much the same thing there is no point in my telling you how much it cost.  It took two weeks with an average of about two people working per day.