I hate to break this to you, but 48,000kW of gas at the current cap is £4,800. I can't see how you are going to get cheaper bills with or without an ASHP - at least in the winter. Can I ask how big your house is? That amount of heat is crazy. But we are also in the coldest snap for years so it's going to need a lot of kW regardless of gas or ASHP - it's just cold outside right now.

Also, for your use, that seems a very small heat pump?! I have a 12kW and I've used 5500kw on my heat pump this year. At a cop of 3 you are looking at 16,000kw - which is still a crazy amount. I just can't imagine a 11kw heat pump is suitable. What are your weather comp settings?

Thank you for getting back to me so quickly - comp curve is around -1 50c and 15 40c - tried to attach a pic but it’s not letting me. House is approx 400sqm plus over 2 floors. The company initially said I needed a 24kw but after doing a heat loss survey they said a 11kw would be sufficient. I’m starting to think that is because of the location I wanted the ashp to be - a 24kw wouldn’t have fit. At my wits end now with all this - wish I could just go back to the gas boiler but want to explore my options so any help is much appreciated

48,000 kWh of gas into an 80% efficient boiler would give you 38,400 kWh of heat.

An ecodan running at a SCOP (note the seasonal bit there) of 3.25 (probably realistic at those flow temperatures ) would need 10,971kWh of electricity. At the current backstop rate that’s £3730

Still cheaper than if you were on gas. Don’t look at the cost now, look at the cost for the year.

@hughf the rate at the moment for elec is 0.48pkw for me so would be over £5k 😞 

my sister is dead against smart meters for her own reasons so that isn’t an option for us atm 

@parmstar tell your supplier you’re struggling to pay, they’ll put you onto prepayment and you’ll automatically end up on the backstop rate. Easy way out of your excessive electrical contract

😀

Your sister might well be dead against smart meters… I’m dead against paying council tax and a TV license, that doesn’t excempt me from those - just like being ‘against’ smart meters won’t excempt you from ending up with one. Although I fail to see the relevance of smart meters to the cost of your running your heating?

Excellent idea thank you Hugh - re smart meters it may work out slightly cheaper as we have a battery with our solar install so could charge it on a cheaper rate overnight approx 10pkwh 

Posted by: @parmstar

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Excellent idea thank you Hugh - re smart meters it may work out slightly cheaper as we have a battery with our solar install so could charge it on a cheaper rate overnight approx 10pkwh 

Please give us more details, are you currently on a TOU tariff?

If you’re paying 48p/kWh then that would suggest so. In which case there are some optimisations to your heating strategy that can be done to maximise the use of the off-peak rate.

My comment about moving to prepayment was tongue in cheek by the way…

@hughf 🤣 I suspected as much. I checked my recent bill and I am on the capped rate - they itemise it slightly differently in that they show a deduction  as opposed to charging it at 34pkwh.

Posted by: @parmstar

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@hughf 🤣 I suspected as much. I checked my recent bill and I am on the capped rate - they itemise it slightly differently in that they show a deduction  as opposed to charging it at 34pkwh.

OK, so you are paying 34p/kWh - good... Then my above maths adds up.

We just need to get these settings tweaked so that the weather compensation is at it's most optimal. Do you have a copy of the heat loss calculations for the property?

When you say thermostat, do you mean the Ecodan controller, or an external thermostat like a nest/hive/other?

@hughf thank you for your help with this.

I don’t have a copy of the heat loss calcs but I could try to get them from the installer.

I have a ecodan controller with matching thermostat which is located in the hallway

Please provide some photos of these items so we can identify versions etc….

please also photograph the unvented cylinder and associated pipework