Last seen: Jan 11, 2026
Yes the unit always performs its defrost cycle, every 40 minutes, and the ice always clears. With the evaporator at -23C when it starts its defrost c...
Thank you. The pipe work is now insulated. Finding a heating eng that knows Hitachi units in this area is difficult. However, as you said a quali...
It sounds like its ice build up and does not sound good. Looking at the algorithm it looks like I am set to the Jo-0 setting, but I don't fully under...
I suspect it's ice build up. Just does not sound right.
JamesPa Could I ask for your interpretation of the defrost algorithm for the heat pump? I am seeing a defrost at around an outside starting tempera...
I did manage to find the spec on the HP and that it can only modulate down to 2.1Kw. And very few other HP on the market get much lower. I have bou...
James Thank you for your help. I will work over the next week to try and produce the data requested. This is still new to me so still a step learn...
James I understand your point about turning the heating off and on or up and down and the resulting effect. Today the one room thermostat controll...
Re the chart that I posted. Could someone comment as to why the subsequent defrost cycles do not perform as per the the first at 3.30pm?
Just to add. As the system is not that common I have been unable to find anyone local who knows anything about the system or what I can do to fix it....
Re the chart. I should of added more info. The first part of the chart shows the performance during the day with one defrost occurring at 3:40pm....
- 26 Forums
- 2,406 Topics
- 54.6 K Posts
- 442 Online
- 6,092 Members
Join Us!
Worth Watching
Latest Posts
-
RE: Post-Traumatic Heat Pump Stress Disorder
Sorry to heat that - it should be possible to improve o...
By JamesPa , 11 minutes ago
-
RE: Heat pump not reaching flow temperature
@jamespa system design was for 40 degrees FT at -2 degr...
By DaveC , 14 minutes ago
-
RE: GSHP WOES! Midland based engineer recommendations?
@editor That is very kind! Thank you so much.
By johnbroome , 19 minutes ago
-
RE: Setback savings - fact or fiction?
I've now calculated the minute by minute energy flows d...
By cathodeRay , 21 minutes ago
-
RE: Considering MLCP (Multi-Layer Composite Pipe) for ASHP
@iotum, this is a really good question and you’re right...
By Mars , 23 minutes ago
-
RE: Recommended home battery inverters + regulatory matters - help requested
That matches the TN-C-S diagram here Your post crosse...
By JamesPa , 24 minutes ago
-
RE: Rate the quality of your heat pump design and installation
@razz stick with it. There's loads of advice on here. ...
By Stopbar , 1 hour ago
-
RE: ASHP Energy Consumption: Aira 12kW heat pump
@wally Hi I am not sure how large your house is b...
By TechnoGeek , 1 hour ago
-
Please help with the settings ecodan
I have a 160 square meter house, first floor 6 radiator...
By nose1972 , 2 hours ago
-
RE: Predicted Heat Loss & Needs from MCS calcs vs EPC vs actual
I've been thinking along similar lines to @tim441 from ...
By Sheriff Fatman , 2 hours ago
-
Thanks, @technogeek. Good to hear about the accuracy. ...
By Majordennisbloodnok , 2 hours ago
-
RE: Advice for a novice on Mitsubishi Ecodan 6kW
In my case it was a very specific pattern of behaviour ...
By Sheriff Fatman , 3 hours ago
-
RE: Vaillant aroTherm not heating with many faults
@ashp-bobba Yeah I'll give it a go, will check filter...
By Anon67 , 3 hours ago
-
RE: RDSAP10 effect on existing heat pump EPC rating?
@transparent Perhaps the names at the end of the docume...
By Toodles , 3 hours ago
-
RE: Heatpunk Floor plan issues
@jamiejones85 A2A they will design on dynamic heat loss...
By ASHP-BOBBA , 4 hours ago
-
RE: Fan unit Making terrible noise HELP!!
can you post a video looking inside, at and through the...
By ASHP-BOBBA , 4 hours ago
-
RE: Power outages and storms: A surprisingly good DNO experience
Agreed, which is no more nor less than a customer shoul...
By Majordennisbloodnok , 21 hours ago
-
RE: Running from backup generaor in powercut?
@batpred In our case, 3 times each day when the Octopus...
By Toodles , 22 hours ago
-
RE: New Fogstar 15.5kWh upright solution
@batpred Here's the latest Fogstar ready built pack....
By Bash , 24 hours ago

