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Last seen: May 29, 2025
@potatoman As no one seems to be obliging, I attach a diagram. The idea is that only bypass flow goes through the tank when necessary so it is undistu...
@trebor12345 The Auto function is supposed to adapt automatically and select the right curve in constant pressure mode. By default the pump is set to...
@trebor12345 Your house is remarkably similar to mine, layout included. I have 185 sqms with 4 beds and 2 baths, same size lounge with exactly the sa...
@trebor12345 Use the internal private messaging system on this forum.
@trebor12345 Re your question about changing setting to controlled DT, this may be worth trying if your current DT is 1C as the heat pump will automa...
@trebor12345 There doesn't seem to be anything obvious on the refrigeration cycle as the temperature ups and downs look logical. However your DT is e...
@trebor12345 I can send you a service manual however it is very large (200MB) so exceeds the file size limit here. If you can send me an appropriate ...
@trebor12345 The penny has finally dropped. I thought you were describing defrost sequences. If you say that this happens at 20C OAT, it is not norma...
@trebor12345 @jamespa From the calcs you sent, your house conforms with modern insulation standards e.g. roof u-value 0.11. Your overall heat loss is...
@trebor12345 The heat exchanger function is the same regardless of whether it is inside or outside. Your heat pump is a 7kW unit, not 3kW as per y...
@trebor12345 By way of further explanation, in cooling mode the compression cycle of the heat pump reverses i.e. the gas flow goes in the opposite d...
@trebor12345 Firstly, the brochure description of the Hitachi says that it definitely uses hot gas bypass for defrost as per the process I described...
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Degrees of Separation
Latest Posts
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RE: HeatGeek vs Octopus surveys: puzzling disparity - any ideas why?
Hi, sorry that I have been absent for a while. I'd like...
By baroquebank , 2 hours ago
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RE: To re-pipe or not to re-pipe? Moving from oil boiler to air source heat pump.
@penval, really useful update. After all the discussion...
By Mars , 6 hours ago
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RE: Who's your electricity provider and what's your tariff?
@papahuhu I prefer to look at it simplistically. We d...
By Old_Scientist , 1 day ago
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RE: How Accurate Is My DIY Heat Loss Calculation?
D'oh - of course. I shouldn't post before my brain is f...
By Old_Scientist , 1 day ago
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RE: Questions about A2A for heating as well as cooling
@rob-of-york I would concur with the underfloor insulat...
By Toodles , 1 day ago
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RE: New Vaillant Arotherm controls link to existing thermostats ; wired vs wireless
Nothing attached! I have rads but UFH makes the case ...
By JamesPa , 1 day ago
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RE: Cooling with air to water heat pumps
Passive cooling should always be the first call. Keep ...
By JamesPa , 2 days ago
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RE: Do I add Air Con or MVHR to existing A2W ASHP?
@rob-of-york Thank you, I’m thinking along these same l...
By Toodles , 2 days ago
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@Mars Good questions! The downstairs unit did the maj...
By Rob of York , 2 days ago
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RE: Volumisers in Heat Pump Systems: Does Placement Matter?
@dave, I think @jamespa has probably identified the mos...
By Mars , 3 days ago
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RE: Plug and play solar. Thoughts?
My thought is simple. Bring it on and bring on plug in...
By JamesPa , 4 days ago
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RE: Heat Geek mini store vs pump size
Yes I agree, that’s why Heat Geek have most likely sele...
By Tomtheheatingengineer , 4 days ago
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@tomtheheatingengineer, thank you, and welcome to the f...
By Mars , 4 days ago
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RE: Is the "divide by 2900" rule still valid?
Really flow rate is a pipework limitation not a water p...
By JamesPa , 5 days ago
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