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!
Mitsubishi Ecodan return flow temperature same as weather curve temperature
Hi,
I have an Ecodan heat pump configured with a weather compensation curve for underfloor heating. From my understanding, the flow temperature (THW1) should align with the set temperature on the curve that corresponds to the outdoor temperature. However, when I check the thermistor temperature or the commissioning wizard, it appears that the set temerature is the same as the return flow temperature (THW2) instead of the expected flow temperature (THW1). Is this OK or should the flow THW1 temperature be the same as set temperature in the curve?
I'm not really sure how it works temperature-wise with UFH so someone else will maybe be able to answer this but is UFH your only heat emitter or do you have radiators or fan coils as well?
With radiators it should be your flow temperature that produces your set temperature but they are not the same. UFH usually runs at lower temps.
My current system flow temperature is 32º producing my set temperature (room temperature) of 22.5º. The return temperature is 27º - my system uses radiators as emitters. The difference between flow and return temperatures is usually less for UFH.
It may help if you share the details of your system.
@borkov, I’ve reached out to Mitsubishi about your issue, and they recommend contacting their Homeowner Helpline at 0161 866 606.
If you’re connected via MelCloud, they can also review your system remotely, looking at the Delta T over recent heating and hot water cycles to give more specific advice. They may ask for details to help identify if it’s related to a defrost cycle, whether heat transfer into the UFH circuit is an issue, or if the thermistors might be incorrectly positioned (e.g., THW2 on the flow pipe).
Get a copy of The Ultimate Guide to Heat Pumps
Subscribe and follow our YouTube channel!
I only have UFH. The system is now running for the third season, and both the heating and DHW are functioning well, with no complaints. I don't think the sensors are switched, as THW1 temperature is higher than THW2.
However, I still want to resolve the issue or find the setting (if it exists) where I can select which sensor (THW1 or THW2) follows the WC temperature. Or perhaps there is something not right with my heat pump.
@borkov is calling the Mitsubishi helpline an option?
Get a copy of The Ultimate Guide to Heat Pumps
Subscribe and follow our YouTube channel!
Yes, it is. I just want to check it out first on the internet to see if someone has had the same experience.
- 26 Forums
- 2,691 Topics
- 63.1 K Posts
- 503 Online
- 7,100 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
-
RE: Say hello and introduce yourself
@watcher Encouraging except that a bungalow is probably...
By Toodles , 4 hours ago
-
RE: How do I set up Tesla Powerwall export for saving sessions since AI Takeover?
@papahuhu We might well have found that a much smaller ...
By Toodles , 6 hours ago
-
RE: GivEnergy inverter tripping due to over-voltage?
Yesterday i had a single overvoltage event. But that mu...
By Tim441 , 11 hours ago
-
RE: Design Of Cascade System Replacing Undersized ASHP
I don't know the full details of your house or installa...
By Temperature_Gradient , 12 hours ago
-
RE: Summer heat is becoming the new winter cold in the UK. What are you doing about it?
Some pics of my heat solutions… Bought the shut...
By Watcher , 12 hours ago
-
RE: Moving growatt axe batteries
@etchedpixels just been informed that you can’t have ba...
By David999 , 24 hours ago
-
RE: Anyone have experience with Daikin Multi+ for air to air & hot water?
Maybe, just maybe, if you are prepared to leave the doo...
By JamesPa , 24 hours ago
-
RE: How to heat a bathroom when using an air to air heat pump?
You can air/air a bathroom with a suitable ceiling or o...
By EtchedPixels , 24 hours ago
-
RE: Plug and play solar. Thoughts?
They've been extensively tested by folks like the Germa...
By EtchedPixels , 1 day ago
-
RE: Electricity price predictions
@majordennisbloodnok Similar, although no heat pump h...
By IanMK13 , 1 day ago
-
RE: vaillant arotherm plus - Failure - DHW
As expected it failed to run late yesterday with the sa...
By trebor12345 , 2 days ago
-
RE: Minimum and Zero Disrupt Heat Pump Installations
Personally, I don't always rate the "payback on install...
By HeatNoob , 2 days ago
-
RE: Adding additional Solar Panels to a DC coupled battery system
@transparent thanks. Will be sure to keep a record of s...
By bontwoody , 2 days ago




