Can pre-warming water from a heat battery reduce the need for a higher kw boiler?

[Roger440]

3 hours ago, Pete lea said:

 

I could lie and say eco reasons etc, but really I just don't like it, I didn't want my kids cooking with it (switch to induction and electric ovens already) and I don't like the small chance that it could leak carbon monoxide (even though we have a detector and have regular services etc).  So not necessary a logical argument for most people.

 

You know that gas is by far your cheapest option?

 

So no, its not logical, but its your cash!

[Trw144]

17 hours ago, Pete lea said:

 

I believe Octopus Go is still at this rate? Although it may have jumped up since, I'm fixed till may 2023 but hopefully going to switch when my Batteries and Solar PV get installed.

 

Yes, I had assumed it had gone but still there - needs an electric car (which I have on order), so going to order 22kW Sonnen and use it to charge on the cheap rate overnight (the battery can then come with me to the new build).

[Pete lea]

19 hours ago, Roger440 said:

 

You know that gas is by far your cheapest option?

 

So no, its not logical, but its your cash!

 

I think the general consensus is that moving away from Gas is a bad idea unless you can get an efficient ASHP/GSHP with at least a SCOP of 3.  The issue was our Microbore pipework and newly decorated downstairs and my wife didn't want to ruin that.  Our upstairs carpets need replacing so perhaps we could take up some floorboards and replace the pipework that way, is this a common method? Or has anyone installed it this way?  

 

I'm going to not make any replacements to heating this winter and focus on reducing our output (insulation + MVHR).  I'll contact an ASHP installer in the new year and see what they can do.

 

Thanks for everyones help. 

[JohnMo]

As your leaving things in place, you really need to do some experiments.

 

Get your heat loss sorted out, then slowly ramp down your boiler heating flow temperature (leave a couple of days, and make sure you meet the thermostat setting).  If you can get it down to 40ish, then a heat pump is doable with your existing pipework.  You will need a decent buffer to allow you to get the circulation rate the HP demands.

 

Almost any heat pump these days will do in excess of a CoP of 3, it's normally the implementation that screws things up.