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Last seen: May 18, 2026
Are you saying that there is a loss of 8C from heat pump to rad. Thats a lot - why? If thats right then its not surprising rads are too small! &nb...
Air comes out of solution over time. I had to bleed one radiator every second day for a month after the installation was done and only the other day ...
I presume he didnt say why? I dont personally understand how this can be the case (so suspect BS) but of course willing to listen to arguments. &nb...
Well that puts a different light on it altogether! Radiators not getting warm would be due to one or more of (a) valve blocked - note that TRV pins...
@jaynieq I wish you luck with this one. I think the main thing I am telling you is to focus (when discussing with any plumber) on the water hammer an...
Thats good. Keep the faith, rad swaps are easy and rads are dirt cheap. Even I can do 2.5 a day, I am not a plumber and absolutely detest plumbing!
Total and complete madness! Better would have been to leave the upstairs rads, make the downstairs ones bigger if there is room, and drop FT, or just...
All sounds good and like you know what you are doing. Radiator balancing can be tedious and the poor control that LSVs give really doesn't help. I ha...
Firstly welcome to the forums. I hope you are running your heat pump 24*7 with any TRVs and thermostats set well above the desired temperat...
(Almost) all heat pumps do defrost by taking heat from the water in the emitters and using that to melt the ice. This causes the flow temperature to ...
From first principles I would say: Definitely design for a single low flow temperature, not different flow temperatures. Definitely calcu...
This is actually normal, or at least its more or less what I see with my Vaillant and there is an obvious logical explanation. The heat pump has to w...
Latest Posts
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RE: ASHP Capacity loss with aging
This is a good question. The short answer IMO is yes, c...
By Mars , 2 hours ago
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RE: Daikin Altherma 3 with Fan Coils in Puglia (Italy)… Sanity Check on System Operation
Welcome @simon_jm, and this is not a dumb question at a...
By Mars , 3 hours ago
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RE: Loud noises in the night - and one for the toolbox?
Brilliant bit of lateral thinking, and a useful one to ...
By Mars , 4 hours ago
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RE: Setback savings - fact or fiction?
Yes, also the higher OAT end is possibly a smidge high ...
By RobS , 5 hours ago
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RE: UK warm homes plan - how can it be delivered?
@bobflux My view is that regulation for consumer pro...
By Batpred , 7 hours ago
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Hi Mars, I've sent you a request to connect me with a...
By sttpd1917 , 8 hours ago
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RE: Sizing an ASHP; Heat loss and kW
Annual consumption is almost certainly better than an E...
By JamesPa , 12 hours ago
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Grant Aerona R290 (15.5kW) - How is DHW Target Temp calculated?
Hello all, We have just had a Grant Aerona R290 insta...
By TaffontheTaff , 13 hours ago
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RE: Advice on Vaillant Sensocomfort
The latest Vaillant announcement I saw said that they w...
By JamesPa , 17 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 , 1 day 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 , 1 day 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 , 2 days ago
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RE: Vaillant Sensocomfort Time
Thank youy for the pointer. I think I have managed to ...
By ispookie666 , 2 days ago
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RE: Forum updates, announcements & issues
I have been doing a lot of work on the site lately and ...
By Mars , 2 days ago
