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Heating not coming on with air source heat pump

Eckie
Posts: 1 Newbie
Hi all, looking for some advice. We have just had a Grant Heat Pump installed. The only issue we have is the heating is not coming on as scheduled. The water cycle takes precedence, of course, but even when there is not hot water demand the heating will not kick in. The only way we can get the heating on is to either turn the water off or reduce the water temperature set point to 45 degs C, from 55.
Has anyone else experienced this and what might be the solution?
Thanks
Has anyone else experienced this and what might be the solution?
Thanks
0
Comments
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Can you not ask the installer to return and sort it out?1
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There really isn't much point in asking us to guess how yours has been installed or set up unless you can tell us exactly what you've got, how its been installed and how the controls and parameters have been wired and configured. There are far too many variables.
Have you checked the installation and user manual to compare how it should be configured against the installation and control settings on your equipment.
If it's not working as it should or you don't understand how to operate it then get the installer to sort it out.
Never under estimate the power of stupid people in large numbers0 -
What’s the desired house temperature? It won’t come on within it’s scheduled period if it’s already warm enough. Mine was fitted 4 weeks ago and it’s never had to do a heating cycle yet. As a side note, the installer should ideally have set the heating to run on weather compensation so it looks after itself rather than on a schedule. You’ll appreciate the efficiency increase come winter!Smart Tech Specialist with Octopus Energy Services (all views my own). 4.44kW SW Facing in-roof array with 3.6kW Givenergy Gen 2 Hybrid inverter and 9.5kWh Givenergy battery. 9kW Panasonic Aquarea L (R290) ASHP. #gasfree since July ‘230
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Eckie said:Hi all, looking for some advice. We have just had a Grant Heat Pump installed. The only issue we have is the heating is not coming on as scheduled. The water cycle takes precedence, of course, but even when there is not hot water demand the heating will not kick in. The only way we can get the heating on is to either turn the water off or reduce the water temperature set point to 45 degs C, from 55.
Has anyone else experienced this and what might be the solution?
Thanks
All pure guesses of course and you really need to provide a lot more info.
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Eckie said:The only way we can get the heating on is to either turn the water off or reduce the water temperature set point to 45 degs C, from 55.Reed1
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DougMLancs said:As a side note, the installer should ideally have set the heating to run on weather compensation so it looks after itself rather than on a schedule. You’ll appreciate the efficiency increase come winter!0
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Very nearly all do (although less knowledgeable installers might bypass it) and it’s mandatory for an MCS installation in the UK. Not all call it that mind you, some call it something like AI or auto-adaptation. Some ground source models don’t however or the Dream stuff you see on eBay. A modulating heat pump without some form of weather compensation isn’t worth having.Smart Tech Specialist with Octopus Energy Services (all views my own). 4.44kW SW Facing in-roof array with 3.6kW Givenergy Gen 2 Hybrid inverter and 9.5kWh Givenergy battery. 9kW Panasonic Aquarea L (R290) ASHP. #gasfree since July ‘230
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I have a Grant (I think with Installation Pack C) and the set-up can specify DHW Priority (as you seem to have) and maximum time for DHW and minimum time for CH (during a DHW heating cycle); mine are set as following:
(31 21) Maximum DHW time = 60 minutes(31 22) Minimum CH time = 0 minutes
I think this means once a DHW cycle starts it will be 'on' for 60 minutes (even though it might reach the desired temperature in less than that); and CH will not run at all during that time. This might be what's happening with you.
(NB. these settings of 60 and 0 are recommended by Grant in their installation guide)
My installer had set the DHW cycle for 3 x 1 hour periods throughout the day, which is way too much for my needs, so I reduced that to once, in the afternoon when outside temp is highest for most efficient DHW heating.
I would suggest checking the "31 nn" parameter values on the un-friendly controller.0
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