New Install - Heat Pump vs Combi

TractorFactor

Which should I go for if I am going to be living in the property for 15+ years?

We got an old boiler in our house replaced about 7 years ago from a tank to a combi.  It resolved a few problems and we probably broke even on the cost savings.

Now moving to a new house.
But it's a question of whether heat pump setups are cheaper to run?
I'm all for what is good enviromentally but also focused on costs as we won't have a lot of spare money.

I've done a quote with EDF who suggest with the grant, I'd still have to pay around £8500 for a heat pump.
When we got our combi put in, it cost between £4000 and £5000.

According to one website, this means (I think?) the cost savings between heat pump vs boiler would take 24 years to break even.

3500 (8500 heat pump install - 5000 combi boiler) / 146 (approx savings PA of a heat pump vs combi) = 23.97.

That doesn't look too attractive.
Although I'd be interested in Solar at some point, it's very low down on the list.

Reed_Richards

At current prices for gas and electricity the running cost for a gas boiler and a heat pump should be much the same.  There's always a danger that the government will shift some of the surcharges on electricity onto gas, it's the sensible thing to do if you want to discourage fossil fuel usage but governments aren't know to be particularly sensible.

I suggest you try Octopus for a quote, they might beat EDF.  I assume the quote is for a full heating system with the radiators as well; you're not clear about this.   

TractorFactor

Reed_Richards said:

I suggest you try Octopus for a quote, they might beat EDF.  I assume the quote is for a full heating system with the radiators as well; you're not clear about this.   

Yeah, most of the radiators are a little old.
We'd look to get some/most of them replaced with either option anyway.

Just looked at Octopus, who said they can't install but I need to do the quote properly (I may have clicked a few wrong options).

Although another issue I need to remember for the future is that you can't use Hive with heat pumps (apparently?).
We really enjoy the flexible nature of Hive and it works for us.

Scot_39

Yoh might want to check any govt plans for domestic gas heating depending on location WM or Holyrood (Cardiff / Stormont if policy devolved their too).

Scottish Greens at one stage were more aggressive on dates ' than Cons - who werd rolling back dates - but Labour vowed to pull some back (ICE 2030, 2035, 2030 sage etc).  Arguably public push back on green plans broke their tie with Harvie as energy minister and Scottish greens in Bute House agreement..

Heat pumps will work a little differently from conventional gas central heating.

In that they are best run at much lower flow temperatures.

That doesn't mean they cannot be controlled flexibly in terms of room temperatures etc - they may just need different lead times on changes.

Just as you might have found if dropped radiator flow temps during crisis - you might have had to turn the gch on several minutes earlier in morning or run a little longer etc.

As they may not necessarily be quite as responsive - lower power output as a rule vs combi peak power and lower flow temps (but these can be mitigated with "larger" radiator output btu/ kW ratings)



Although hive are part of British gas, the Hive website says  they themselves supply heat pumps - installed by British Gas -  I am sure they will have smart apps and controllers to suit.

You could ask for a quote from their site too.

And other brands will have their own smart programmers and zoned trv control options etc.

Have you tried local installers rather than the energy companies.  They may not be as expensive.  And may offer a more bespoke / flexible selection of kit.

Have a look in the dedicated heat pump section.  You may find recommendations and solutions to overcome your specific Hive issue.

Scot_39

Reed_Richards said:

At current prices for gas and electricity the running cost for a gas boiler and a heat pump should be much the same.  There's always a danger that the government will shift some of the surcharges on electricity onto gas, it's the sensible thing to do if you want to discourage fossil fuel usage but governments aren't know to be particularly sensible.

I suggest you try Octopus for a quote, they might beat EDF.  I assume the quote is for a full heating system with the radiators as well; you're not clear about this.   

As more stop using gas - that alone may be liable to increase gas network costs per consumer - especially given who has been buying up NG share of the gas network  (let's hope Ofgem do a better job than Ofwat in the mid 2000s onwards). 

Currently c24m homes but as more fit heat pumps fixed cost x / 24m --> cost x+ inf / lower yym etc.

And given carrot of £7500 not working that well and only ever temporary until prices drop (sic!) (like EV grant incentives and road tax exemptions etc  have been) - the logical next step is the stick - e.g. CO2 generation levies on domestic gas  - or out and out bans.  Not an obvious vote winner - but with Milliband et al, riding a massive majority - who knows.

Remember the aim of greens is zero domestic gas.  Scottish Greens even published a calendar for it. 
Starting with new installs in 2025 and standing occupiers replacements in 2030 - although SNP have now delayed these dates after abandoning Bute House agreement with Harvie et al.  2025 == 2028 ?? 2030 == xxxx.  Possibly earlier for landlords and new buyers - who were going to be forced to go zero emmissions with first few years etc.  But iirc 2045 final ban still stands.

FreeBear

Reed_Richards said:

At current prices for gas and electricity the running cost for a gas boiler and a heat pump should be much the same.

If you are doing the comparison using standard variable rate prices, then a HP may cost a little more than gas. Use a tariff such as Octopus Cosy (or even Agile), and a HP could be 50% cheaper to run. Throw solar PV and batteries in to the mix, and the running cost could fall further.

In the current market, it is not a simple calculation. However, if I were shopping for a new heating system today, a heat pump would be my preferred choice.

Reed_Richards

TractorFactor said:

Although another issue I need to remember for the future is that you can't use Hive with heat pumps (apparently?).
We really enjoy the flexible nature of Hive and it works for us.

You can use Hive with a heat pump or a gas boiler and it works badly with both.  With a gas boiler it does not support OpenTherm so you don't get some of the sophisticated control features that would save you money.  With a heat pump it can just turn the pump on and off (as with the gas boiler) and you tend to get better control by using the manufacturer's dedicated controller.  

TractorFactor

Reed_Richards said:

TractorFactor said:

Although another issue I need to remember for the future is that you can't use Hive with heat pumps (apparently?).
We really enjoy the flexible nature of Hive and it works for us.

You can use Hive with a heat pump or a gas boiler and it works badly with both.  With a gas boiler it does not support OpenTherm so you don't get some of the sophisticated control features that would save you money.  With a heat pump it can just turn the pump on and off (as with the gas boiler) and you tend to get better control by using the manufacturer's dedicated controller.  

Hive works for us.
We know it's limitations but the only thing we really like is the simple schedule / on / off feature and that we can boost it away from home or using our voice (via Alexa).

If I can do that with a Heat Pump controller, then I won't bother getting Hive installed but at the end of the day, it will boil (pun intended!) down to cost.

matt_drummer

TractorFactor said:

Reed_Richards said:

TractorFactor said:

Although another issue I need to remember for the future is that you can't use Hive with heat pumps (apparently?).
We really enjoy the flexible nature of Hive and it works for us.

You can use Hive with a heat pump or a gas boiler and it works badly with both.  With a gas boiler it does not support OpenTherm so you don't get some of the sophisticated control features that would save you money.  With a heat pump it can just turn the pump on and off (as with the gas boiler) and you tend to get better control by using the manufacturer's dedicated controller.  

Hive works for us.
We know it's limitations but the only thing we really like is the simple schedule / on / off feature and that we can boost it away from home or using our voice (via Alexa).

If I can do that with a Heat Pump controller, then I won't bother getting Hive installed but at the end of the day, it will boil (pun intended!) down to cost.

If you end up getting a heat pump you will need to get your head around the fact that they do not work like a gas or oil boiler.

On/off control isn't really enough.

With a gas or oil boiler, it just burns stuff, and the efficiency is pretty much fixed within a little.

The efficiency of a heat pump can vary wildly depending on how it is installed and operated.

The same heat pump in two different houses could be 200% efficient or more than 500% efficient, a massive difference.

Turning heat pumps on and off doesn't necessarily use less electricity than just letting it run continuously.

Zones and trvs often cause problems with heat pumps.

A Hive controller will be worse than using the manufacturers controls with all heat pumps that I am familiar with.

A heat pump is not a gas or oil boiler and if you treat it like one then it is likely to to be a disappointment.

Adrian_Dorr

At worse a heat pump will be similar in running cost, if set up correctly, which usually means not using a timed controller, but mostly keeping the house at a constant temperature. You can reduce that a little at night or when you’re out. 

Give boxt a try, they installed mine last week and were of a similar price to octopus, but more flexible.