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!
Air in the heating system
Our underfloor (ASHP powered) system has air in it. I can hear water trickling through the pipework at night and every day canbleed air out of the heated towel rails.
I know this makes it less efficient and have an engineer visiting next week, hopefully to rectify it. He has already been once and identified that the pressure gauge on the heating expansion vessel isn't working so always shows zero pressure instead of what I'm told should be about 1 to 2 bar.
With the current very cold weather our electricity consumption has of course gone through the roof and I'm hoping to see some improvement from fixing this.
But how does the air get into the system? How do you eliminate it? There is no sign of fluid leaking out but the plumber thinks it should be topped up via the fill tube (which the installers helpfully put downstairs while the pressure tank and other pipework are upstairs!).
Grant Aerona HPID10 10kWh ASHP
Few ways. Easiest is to isolate return manifold, close all zones (loops) but one and install hose to return drain point and open. Then open filling loop unit air clear. Repeat for each loop.
seemingly very few installers know yet alone do this
These guys have "deaerators" that can remove microbubbles that are left flowing around a system, might improve matters. They also sell exotic "vacuum degassers" I think those need electric mind, to directly remove dissolved gasses.
Never used any of them myself, we have conventional rads with bleed valves all over the place- every time I have ever had the system emptied and refilled it has taken weeks to settle down and stop gurgling. When I refill it I wish we had a clever pump that jerked on/off as some now do to help clear air locks. It's only done every 5 years/never, so no worries. I've trawled around the website looking for pressure versus flow on them, they just say "low pressure drop".
- 27 Forums
- 2,746 Topics
- 64.5 K Posts
- 780 Online
- 7,149 Members
Join Us!
Installer Finder
Degrees of Separation
Latest Posts
-
Have you considered keeping your FF boiler and suppleme...
By Old_Scientist , 8 minutes ago
-
RE: Who's your electricity provider and what's your tariff?
@toodles I invested on Miele a pair of frodge frozor wh...
By AgentGeorge , 2 hours ago
-
RE: Flushing system, cleaning and inhibitor
Flush and fill all complete. Octopus kindly gave us a...
By Old_Scientist , 2 hours ago
-
RE: Wood burner with ASHP - direct air?
For what it's worth I installed a wood burner in this o...
By BlizzardGreen , 3 hours ago
-
@editor Thanks for your response and recommendations. ...
By DavidB , 10 hours ago
-
RE: Do I add Air Con or MVHR to existing A2W ASHP?
I think I saw a diagram for an exhaust air dhw tank wit...
By JamesPa , 24 hours ago
-
RE: Indevolt Batteries UK Support & Info Thread
Thanks, however that's an answer to a subtly different ...
By JamesPa , 3 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@toodles Such elegant symmetry. look at my lumpy bag of...
By Papahuhu , 4 days ago
-
RE: PV and battery long payback - sense check query
Quite probably not, but you can get a 32A relay and a S...
By JamesPa , 4 days ago
-
RE: Starting Our Heat Pump Journey: 1962 build 3 bed detached house
@ian-s Look forward to making contact soon! Regards, To...
By Toodles , 4 days ago
-
I don't notice mine defrosting, and most of the time Im...
By JamesPa , 5 days ago
-
RE: Do I need to change the control unit when replacing my Ecodan Air Source Heat Pump
Kind of you, @calumm, but it was @f1p who did the heavy...
By Majordennisbloodnok , 6 days ago



