Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws

Install the app
How to install the app on iOS

Follow along with the video below to see how to install our site as a web app on your home screen.

Note: This feature may not be available in some browsers.

Nov 17, 2022
26
0
1
Maidstone
Member Type
General Plumber
Hello.

I’ve lived in the property for 4 years and anytime the pressure got low (0.8 bar) I would use the fill taps to release more water into the system. Ever since British Gas did their annual boiler check about 3 months ago, I’ve had to do this too up method more and more. My pressure is now 1.8 bar which is too high but seems to lose pressure and need topping up every other day. I can’t see any leaks and the pressure reading isn’t changing so any ideas why I’m losing my hot water and heating until I let some more water into the system and then it fires straight back up?
 
F22 / low system pressure.
Do you have a boiler manual? As fault codes will be located in the back of the book.

Pushing the button to check the system pressure should not effect that. 🔘👈

As a rule, I allow 0.4 bar rise on the gauge when the heating is on ( the pump on) give or take 0.1 bar.
As cjg said water expands when heated.

For example let's say at rest the boiler reads 1.2 bar and when the heating is on, it goes upto 1.6 bar or 1.7 bar.
Anything higher that 0.7 bar rise ( say 1.2bar to 2bar) will most likely mean your expansion vessel hasn't got the correct charge.

It may well be that you have a slight leak somewhere on the system, causing the low pressure over X amount days.
Or that it just requires topping up the system pressure via the filling loop, to 1.2 bar at rest. Not left on 0.8bar.
 
Hello

Thanks for the replies. Yes I had taken into account the pressure changes when heating is on but the base pressure level keeps dropping. I’ve had to fill it again today as went down to 0.6 so now back at 1.2 and will be 0.6 in a few days again (sooner if I check on it 🤪😉).

The expansion vessel was recharged as was flat and they checked it again last time and was fine. Dynarod of the 4th Jan so hopefully some answers then if it is a leak. Meanwhile I’m topping it up so more leaking if there is one for another few weeks 😩
 
Hello again.

Another thing I’ve noticed … I have the wireless thermostat set at 20 degrees and the whole house was boiling hot. I checked the thermostat which is next to the boiler and it said 20 degrees (it felt way higher) and the upstairs bedroom was 23 degrees and that’s usually colder. The boiler was on and all radiators were pumping and had been for ages and the control panel on the boiler was flashing an egg timer which it keeps doing. I know this is to prevent it from cycling on and off but again I’ve never noticed it before and it seems to be like the boiler should be switching off but isn’t as wrongly believes it’s still at just 20 degrees. If that makes sense?
 
Position your wireless room thermostat closer to a radiator/heat source for a more accurate reading. Keeping away from windows and external doorways.
Try turning your thermostat down to 19.

Say the place you leave the room thermostat is in cold area, the heating will stay on longer trying to reach the 20° on the wireless stat. If you position too close to a Radiator it will reach temperature and turn off the heating quicker.

Or try putting the wireless stat in the hot bedroom and see how you get on 🥵

Egg timer, engineer to check the filter is clean. Allowing circulation.⏳

I would go for a gas engineer and not dynorod.

Check visually: Filter for a leak, Radiator valves, Visible pipework, External PRV, drain offs etc 👀
 
Position your wireless room thermostat closer to a radiator/heat source for a more accurate reading. Keeping away from windows and external doorways.
Try turning your thermostat down to 19.

Say the place you leave the room thermostat is in cold area, the heating will stay on longer trying to reach the 20° on the wireless stat. If you position too close to a Radiator it will reach temperature and turn off the heating quicker.

Or try putting the wireless stat in the hot bedroom and see how you get on 🥵

Egg timer, engineer to check the filter is clean. Allowing circulation.⏳

I would go for a gas engineer and not dynorod.

Check visually: Filter for a leak, Radiator valves, Visible pipework, External PRV, drain offs etc 👀
Thank you very much for the reply. I will try all of those things as having to top up almost daily now. Have a great Christmas!
 
So … I was away for a couple of days over Christmas. Topped up boiler pressure before I left to 1.5 expecting to return home to the usual 0.6 bar or F.22 error code. Instead boiler was at 2.8 bar and water had discharged from the PRV.

I checked the filling loop (just read this should be disconnected) and one of the valves had been left open. The other I gave to use grips to open/close as the black handle is broken. Clearly I didn’t line it up correctly to turn it off and although not making any noise, must have been trickling water through still.

My questions are:

1. The valve I use grips for, I can hear water flowing through if I turn it clockwise or anti clockwise. Is this normal or do I need to replace the valve?

2. Is it possible I have contaminated my mains water leaving it open slightly or it flowing water when the valve is turned either way?

Thanks again.
 
Update - have now disconnected the filling loop mains end. Another thought - is it possible the pressure loss has been caused by the valve on the flow control end being faulty? Not sure how it could but just a thought as only drops pressure to F.22 levels when not in use?
 
Filling loop needs changing as you shouldn’t have to use grips to turn it off and no you shouldn’t hear water flowing
Thanks. I’m not sure I can remove the other end without draining the system as think the valve on the filling loop itself is what’s stopping the flow. I’ll double check and take a photo in a bit. For some reason my filling loop is where the old immersion boiler used to be upstairs and not under the combi.
 
Thanks. I’m not sure I can remove the other end without draining the system as think the valve on the filling loop itself is what’s stopping the flow. I’ll double check and take a photo in a bit. For some reason my filling loop is where the old immersion boiler used to be upstairs and not under the combi.

Yes you will need to drain
 
Ok thanks. Is it possible this could be the cause of losing pressure?
 

Attachments

  • 9A419B9A-21D4-46EF-984B-DE5BA15C70E8.jpeg
    9A419B9A-21D4-46EF-984B-DE5BA15C70E8.jpeg
    529 KB · Views: 54

Official Sponsors of Plumbers Talk

Similar plumbing topics

We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.