Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!
Ecodan heated DHW outside of timer window, why?
Yesterday at around 9:45am, the Ecodan sprung into action and heated the DHW tank much to my surprise as I have set the timer on the controller to only heat between 1 and 2pm and if we need more I just do a manual 'Heat Now' via the MEL Cloud app. I definitely did not press 'Heat now' on the app.
Almost 12 months since install and I've never seen it do this.
The only thing of note is that the tank was pretty much cold, we had no major need prior to the 1pm heat up, however I ran the hot tap for quite a while (not too long before 9:45am) to see whether there were any bits of warm water left in there at the top (there wasn't). Could this have made the tank hit a minimum temperature that forces the ASHP to heat the DHW? If so, I don't recall seeing a setting for this in the controller.
Mitsubishi Ecodan 8.5kW
4.4kW Solar PV
5.2 kWh Battery Storage
1983 build, 300mm loft insulation, cavity wall insulation (beads)
The only other scenario I've noticed a DHW heating run happen is when restarting the system after a power cut. I've seen the tank reading get pretty cool and it still wait for the end of a heating-prohibited schedule period.
By the way, if you want a DHW run faster, start it on the controller rather than the app: rightmost screen button then leftmost on mine, then back out to the front screen for it to activate.
@mjr Thanks, yes mine has been at 8 degrees C some days and still waits until the end of the prohibited window, so very strange.
TBH when I press DHW 'Heat Now' on the app or the tap on the thermostat, every time it's almost instantaneous, it's the heating where I find there is a ~15 minute lag before the Ecodan fires up/stops when the temperature is altered. My main controller is in the loft, but thank you for letting me know.
Mitsubishi Ecodan 8.5kW
4.4kW Solar PV
5.2 kWh Battery Storage
1983 build, 300mm loft insulation, cavity wall insulation (beads)
- 27 Forums
- 2,778 Topics
- 65.5 K Posts
- 476 Online
- 7,185 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
RE: Replacing Storage Heaters with a Heat Pump in a Stone Cottage
@paul1098 — as we are getting down to the nitty gritty,...
By cathodeRay , 6 hours ago
-
RE: Tesla Powerwall (2) Calibration Cycles
I’ve had two calibration cycles in the last three month...
By Davesoa , 10 hours ago
-
RE: Is This Initial Free Quote From Octopus Trusted Partner Reasonable?
@editor That's a pity, but thank you for checking. I'l...
By ltron2 , 24 hours ago
-
My fifth heat pump book, Heat Pumps Explained, is out n...
By Mars , 1 day ago
-
RE: Who's your electricity provider and what's your tariff?
Just furkled Into the parameter menu. Found the master ...
By AgentGeorge , 1 day ago
-
RE: Analysis of the economics of switching to an A2W ASHP compared to other heat sources
It's interesting that Norway with a much colder climate...
By Rob of York , 1 day ago
-
RE: Review your electricity provider
Happy to add Scottish Power and the review 'dont touch ...
By JamesPa , 2 days ago
-
RE: Is it just me, or does tradesperson timekeeping and communication drive you absolutely mad?
Yes, and I would suggest likely to get worse with more ...
By Batpred , 3 days ago
-
RE: Electricity price predictions
This topic seems more suitable for this thread... I a...
By Batpred , 3 days ago
-
RE: Why are ASHP installs so expensive?
It is clearly difficult to say, there must be cases whe...
By Batpred , 3 days ago
-
RE: Panasonic Free Multi Z and Etherea Internal units.
@dgclimatecontrol Thank you for that information and re...
By Toodles , 3 days ago
-
RE: My Kronoterm Adapt 0312 ASHP is finally installed!
@editor It was serendipitous really. Both my wife and I...
By tomasmcguinness , 4 days ago
-
@mrkfm, I'd also suggest that whenever you're ready, st...
By Mars , 4 days ago
-
RE: Are you planning to use a wood burner to supplement your central heating this winter?
I use my stove daily for backup and comfort. Definitely...
By Margarethomas , 4 days ago




