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!
Red Expansion Tank
@bobtskutter Hi Bob. Daft mistake with the valve.
The red expansion tank is not attached to the hot water cylinder.
I can't find the PSV you mention on the heating side.
Filling the system from 0 to 1.5 did not take long although I did slow it down towards the end. I'm only guessing maybe 5 seconds and then a few more.
The installer did ask me to check the auto air valve on top of the buffer tank to see if wet. Totally dry and always auto open so I don't know if it's been venting air. Maybe that's it!
A few weeks ago the system was drained down so maybe trapped air in the system has suddenly found it's way out. Hope that's the reason and why the pressure only dropped.
Will monitor the pressure over the weekend.
Install 13 April 2024 - 4 Bedroom Brick Detached - Heat Loss 9,281w, Design 45c at -2 - Ecodan 11.2kw R32 - 25L Buffer - 250L Telford Tempest HP DHW - All 16 radiators replaced - Auto Adapt - Mel-Pump app - Octopus Cosy Fixed
10 March 2026 - now 2 x Sigenstor 10 batteries with 8kw Inverter
@bobtskutter Hi Bob. Just a short update to say that the Red expansion tank guage is stable on 1.2 reinforcing my thought that it was air in system. It was drained down 4 weeks ago and maybe the release of trapped air was delayed or maybe I just hadn't noticed it.
I will still keep an eye on it though.
Install 13 April 2024 - 4 Bedroom Brick Detached - Heat Loss 9,281w, Design 45c at -2 - Ecodan 11.2kw R32 - 25L Buffer - 250L Telford Tempest HP DHW - All 16 radiators replaced - Auto Adapt - Mel-Pump app - Octopus Cosy Fixed
10 March 2026 - now 2 x Sigenstor 10 batteries with 8kw Inverter
- 26 Forums
- 2,697 Topics
- 63.3 K Posts
- 797 Online
- 7,106 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
RE: Electricity price predictions
Chinese manufacturing has the ability to be very good q...
By Majordennisbloodnok , 3 hours ago
-
RE: Air source heat pump roll call – what heat pump brand and model do you have?
Forum Handle: GotGordon Manufacturer: Samsun...
By Gotgordon , 14 hours ago
-
RE: Summer heat is becoming the new winter cold in the UK. What are you doing about it?
@ian33a I am not easy with sleep either unfortunately…....
By MK4 , 15 hours ago
-
RE: Renewables uptake near you
In a village of under 40 houses...Conservation Area. I'...
By Tim441 , 1 day ago
-
RE: Home Alone with Home Assistant (previously A Beginner's Guide to ASHP Monitoring)
Great news, @bontwoody.
By Majordennisbloodnok , 1 day ago
-
Haier R290 Super Aqua Monobloc. Output capacity tables.
As I mentioned in my introduction post, I've been consi...
By Singlespeed , 1 day ago
-
RE: Air to air bus grant installer anywhere
I am consistently told by aircon folks (ie air/air) tha...
By EtchedPixels , 2 days ago
-
RE: What is possible with FIT, SEG, Hate Pumps and Batteries?
Thank you, everyone, for your replies. Our FIT provid...
By ian33a , 2 days ago
-
@mk4 And of course, the panels are less productive due ...
By Toodles , 2 days ago
-
RE: GivEnergy inverter tripping due to over-voltage?
I'm trying to get clarity on exactly when the inverter ...
By Tim441 , 2 days ago
-
RE: Samsung Heat Pump – Can't Activate TW2 Pipe Sensor (for Delta T Control)
Autocorrupt seems to be working overtime.
By Majordennisbloodnok , 2 days ago
-
RE: Vehicle-to-Home with a Heat Pump: Is the Technology Ready and Which EV Should I Buy?
I looked into that wallbox a bit more off the back of t...
By Majordennisbloodnok , 3 days ago
-
RE: Say hello and introduce yourself
@jandp awesome system I hope it works out well.
By Judith , 3 days ago
-
RE: Surface mount or bury primaries for heat pump installation?
@bobflux That's the stuff. The installer recommended tw...
By tomasmcguinness , 5 days ago



