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 high pressure at 3 bar
We have a Mitsubishi Ecodan with UFH downstairs and radiators upstairs. The pressure at the water tank is 3 bar.
I have lowered this by bleeding water from the radiators to 2 bar as indicated by the fixed red marker on the pressure gauge.
This has gone back up to 3 bar and there is water coming from all the radiator bleed valves when opened so no air in them it seems.
We have had 2 new towel rails replacing cheap old ones. Not sure if this has anything to do with it.
Any advice on how I can resolve this issue and what might be causing it?
Andy
Something similar happened to me once with a gas system boiler. The filling loop hadn't been closed properly and it was pushing up the pressure over time. You might want to check that.
Posted by: @dorkyparkThe filling loop hadn't been closed properly and it was pushing up the pressure over time. You might want to check that.
That's a good reason to disconnect the filling loop when not in use, in the way that it is designed for!
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
Hi thanks for that, I'm not sure if I'm correct but I seem to remember having to open a valve to add pressure to the system. Would this be the valve that you mean? It was fully open and I've now closed it.
Yes, you would need to reduce the pressure to the correct value for your system (usually 1 to 1.5 bar when cold).
And as @jamespa says, disconnecting the filling loop when not used is the correct thing to do.
@sand I far as I am aware, all systems have two of these valves (one on each side of the mains feed to the red tank; these should both be shut off after any adjustment to pressure. (I may be wrong but all systems I have come across have the two valves and plumbers have told me they should both be shut after adjustments are complete.) Nervously, Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
Posted by: @toodles@sand I far as I am aware, all systems have two of these valves (one on each side of the mains feed to the red tank; these should both be shut off after any adjustment to pressure. (I may be wrong but all systems I have come across have the two valves and plumbers have told me they should both be shut after adjustments are complete.) Nervously, Toodles.
You are correct, but they also come with thumb-turn fittings so they can be disconnected easily. On mine at least its necessary to do this to be sure that the shut off valve is truly shut off.
4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.
- 26 Forums
- 2,618 Topics
- 61.1 K Posts
- 860 Online
- 6,994 Members
Join Us!
Worth Watching
Latest Posts
-
RE: Renewables & Heat Pumps in the News
An article on funding for heat pumps in case anyone is ...
By Jeff , 2 hours ago
-
RE: Indevolt Batteries UK Support & Info Thread
Thanks @editor , @indevolt-uk Subject to any comments ...
By JamesPa , 10 hours ago
-
RE: Share Your Experiences with Heat Pump Manufacturer Support
@seoras Sorry to hear that. I found Vaillant very help...
By JamesPa , 10 hours ago
-
The Watchdog That Watched and Waited
On 9 January 2026, Consumer Energy Solutions collapsed ...
By Mars , 14 hours ago
-
RE: GSHP Kaput After 16 Years: New Compressor or Switch to ASHP? Advice Welcome
Cool Energy in Grimsby sell ground source heat pumps an...
By DerekDeLeon , 14 hours ago
-
RE: Valliant Heat Pump Settings
Thats arguably a sign of a good installer - they unders...
By JamesPa , 15 hours ago
-
RE: Electricity price predictions
Well, we have so many cases where rain water mixes with...
By Batpred , 16 hours ago
-
RE: Two heating zones to one zone
@profzarkov They arent obviously wrong, but the only...
By JamesPa , 18 hours ago
-
RE: Towns water feed to air source heat pump system
The DHW circuit cant be separated (well it could, you c...
By JamesPa , 18 hours ago
-
Solis AC-coupled 3kW storage inverter
Solis AC-coupled 3kW storage inverterPylontech batterie...
By MartinRobinson , 24 hours ago
-
RE: My NIBE ASHP Nightmare: No Commissioning, High Bills and a Hostile Installer
As @transparent has observed above, this is not bad, an...
By cathodeRay , 1 day ago
-
RE: The Grid Says Yes.. Until It Doesn’t: Why Britain's Net Zero Push is Stalling at the Plug Socket
As I was reading this article Mars, I was thinking that...
By Toodles , 2 days ago
-
RE: Tell us about your Solar (PV) setup
Installed in May 2011: 16*Sharp 245 W monocrystalline p...
By txmartyn , 2 days ago
-
-
RE: Say hello and introduce yourself
That doesn't sound 'right' to me. The national Smart ...
By Transparent , 3 days ago
-
RE: Growatt battery disconnected
I doubt this will happen, but I will try and suggest it...
By Eliuccio , 3 days ago
-
Understood. That's why I decided from the outset on a ...
By JamesPa , 4 days ago
-
RE: My experience with 3 heat pump surveys: Heat Geek, British Gas & Octopus
On the litigation, I would not go there and definitely ...
By Batpred , 4 days ago
-
RE: Recommended home battery inverters + regulatory matters - help requested
I suppose if your pv inverter packs up, you have a plan...
By Batpred , 4 days ago
-
RE: New Vaillant aroTherm Plus in black - When will it come to the UK?
Firstly check you are using sound power not sound press...
By JamesPa , 4 days ago
-
That’s the solar up and running, I don’t think it’s the...
By David999 , 4 days ago
-
RE: Seeking ideas / information / commiseration - Pure Drive
I agree with @colinc that you can reuse some of it. A s...
By Batpred , 4 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@toodles Im trying me best to ignore orangeman, I figur...
By Papahuhu , 5 days ago



