Last seen: Dec 18, 2025
Same here @Marvinator80. I have max LWT (in my case 45degC) set to 0degC. To be fair below 0degC I don't reach max LWT, due to continual defrost cycle...
Hello and welcome. The Grant Aerona units are known to spend a lot of time in defrost in winter conditions, usually every 45-60 minutes. That does see...
@mike-patrick I called Grant HQ. They arranged for Olly the local service engineer to attend. Pricey service of the ASHP and system cylinder at £250. ...
The Grant units seem particularly keen to defrost around every 45 minutes when there's high relative humidity and the evaporator refrigerant temperatu...
@misterB consider tariffs such as Cosy Octopus that offer two 3hr low rates a day. If you can get an EV tariff then so much the better 😉
@marvin91 there’s a separate post for weather compensation on Grant Aerona. It’s quite simple. You’ve got the Grant installation manual? It’s a redact...
@mab I have external clunky digital room stat. I think Grant only use these because few if any of their installers understand how to program the Chofu...
Hi there, just to clarify. On the Grant pre-plumb cylinder, the thermostat dial is the hot water thermostat - a simple on/off device to call for hot w...
@mikefl I have a theory the closeness of the outdoor air sensor on the Grant Aerona's may be causing some adverse response. During defrost the outdoor...
Depending on your weather compensation settings, disabling WC and reverting to constant leaving water temperature would work. Depends on what outdoor ...
@roamingbull or disable weather compensation for a short period and revert to constant higher flow temperature. My 10kW Aerona is defrosting every 45 ...
Welcome to the Cosy corner @Toodles. We pay an average of 20.4p/kWh including VAT & standing charge. 88% of our electricity import is at the low r...
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