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Last seen: May 8, 2026
Hi Pat! We have a tiny 2.5kW(thermal, 660W elec) gshp, 4kWp solar, MVHR, 150mm EWI, 30kWh V2G car, 200l DHW tank, 4 bed highly insulated retrofit ho...
I think that did use to be a thing, but it is fraught with difficulty. Mice getting in, mould, stagnent water pools. All of these can be tackled - g...
I think you can make a pretty good guess that any floors installed prior to 1991 will have no insulation. A bit of googling gave U values over time (...
Hard to imagine how a hybrid inverter would be ok here. Imagine you got an Octopus Go tariff, charged up the batteries at cheap rate. Then discharge...
@sunandair You’re right, re-reading I wish I’d said it differently. Comparative measurements will be good! Caring, looking at the data is a great th...
I’ve never heard of a heatpump with MID certification - that would mean a certified accuracy of measurements. You can certainly buy heatpump power me...
I think the compressor would not like to be turned on when it is too cold (hence they often have heaters). Conversely, in warmer weather it may overh...
@cowshed_rich I don't think it's an inverter model - this says not: Perhaps you're right, and it's a "marginal COP" thing due to the DHW t...
That does sound surprising! I expect that you're right - the backup heater is likely to be an inline immersion somewhere. How do you measure the ...
@catapult I’m pretty sure that black thing in your pic is a magnetic water trap. Strong magnets inside pick up bits of circulating rust flaking of...
An Electrician will be able to fit a meter to your gshp system, and I think it's the first step in understanding if it is functioning well. I underst...
@william1066 I think that you're right - dropping the LWT always improves the COP of the compressor. The DeltaT is pretty much irrelevent to the c...
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RE: Advice on Vaillant Sensocomfort
@jamespa Thanks, that’s useful. It also seems the ...
By Batpred , 6 hours ago
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RE: Debugging my legionella immersion heater
I notice this (66 is rather hot) with my legionella cyc...
By JamesPa , 11 hours ago
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RE: DIY Heat Pump Installations: Navigating Legal and Regulatory Hurdles
@transparent I thought you would spot that wind turbine...
By Batpred , 12 hours ago
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UK warm homes plan - how can it be delivered?
@editor Sobering thoughts on your article on the workfo...
By Batpred , 13 hours ago
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RE: Setback savings - fact or fiction?
You are right to be intrigued by it IMHO. SOFAIK it is...
By JamesPa , 20 hours ago
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RE: Octopus Cosy Heat Pump Owners & Discussion Thread
@swwils there is no logic to oversizing a heat pump. It...
By AgentGeorge , 22 hours ago
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RE: Vaillant Sensocomfort Time
Thank youy for the pointer. I think I have managed to ...
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RE: Forum updates, announcements & issues
I have been doing a lot of work on the site lately and ...
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@majordennisbloodnok good advice, thanks for that.
By David999 , 2 days ago
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RE: My Grant R290 9kW Heat Pump Installation
I am following this thread with great interest and than...
By TaffontheTaff , 2 days ago
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RE: Sizing an ASHP; Heat loss and kW
You can't measure heat loss with a website. But you ca...
By JamesPa , 2 days ago
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RE: Estimating true heat loss from twelve months of consumption data
@ian33a — I have a sort of residual interest in this pr...
By cathodeRay , 2 days ago
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Hi, Thank you. So its a Daikin Altherma 3M...
By Lbart68 , 3 days ago
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I have a Contactum CU. Would the below RCBO (descriptio...
By Batpred , 3 days ago



