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Last seen: Aug 13, 2026
Think I’ll claim the no pump in the heat pump thingy 😉😂😂 Davew have you tried a DT check while your system is in DHW mode? That will be a shorter re...
@derek-m not entirely sure but I thought the water circulating pumps are only external pumps. I always thought the ASHP pump is driving the R32 gas/l...
@si-fillo if you find that the pump is already at the slowest pump speed you may be able to slow it further if you slowly adjust the isolation valves…...
Crossing messages again😂 Do you have access to the service menus? If so try adjusting the pump speed to speed one then do an enquiry on the servic...
@si-fillo I would say you definitely need access to the pump speeds. Is it just a single pump system you have? We have a primary flow pump which also ...
@si-fillo it’s possible you have a bespoke installation where the pumps may be off the shelf and don’t respond to the ftc controls. We have 2 indep...
@si-fillo what pumps do you have brand model. are you changing them using the ftc controller or are you doing it manually?
@gotaashp and @Davew is it true that you don’t get cycling when doing the DHW re-heat and this is generally at a higher set temperature?
@cathoderay sounds like a useful trial. Also I’ve noticed reference in this thread to a ‘Boost’ in the morning whereas we have been doing a rise in...
@scrchngwsl so would it be fair to say while the HP is modulating to a reducing temperature, eg. to the set back temperature of say 16c down from 21c ...
@scrchngwsl well spotted you’re absolutely right. I must have read .17 as bigger than .4 So possibly a lower setback, may also favour a Good COP? t...
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Latest Posts
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RE: Problems with sizing a replacement for a Viessmann Vitocal 200-S
Ah. If the 'secondary pump' means a water circulation ...
By JamesPa , 49 minutes ago
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Flow rate is set by pressure created by the circulator ...
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@rob-of-york — thanks for posting this, all very useful...
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The installation is almost done! I've written up two ...
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