Boiler Losing Pressure - I can see dripping from a valve
- Thread starter hoodlum59
- Start date
Sponsored Links
Quite possibly CBW. This was also replaced by BG a few months ago (in fact they did it twice as the original work didn't stay working beyond their original visit). The valve was getting stuck open. That appeared to have been resolved as it no longer stays open after the heating runs.
I have just manually opened the valve and the boiler started to run. I dont recall this happening in the past when I manually opened the valve. Is this right? I did it several times and yes, the loud bang does indeed appear to be coming from here, rather than the boiler.
I also observed the isolator tap on one side was only about halfway open. I have fully opened it now but the bang still happens.
I have just manually opened the valve and the boiler started to run. I dont recall this happening in the past when I manually opened the valve. Is this right? I did it several times and yes, the loud bang does indeed appear to be coming from here, rather than the boiler.
I also observed the isolator tap on one side was only about halfway open. I have fully opened it now but the bang still happens.
Post a pic of the valve and the pipes it is on
Sponsored Links
ps, that drip is as a result of opening the tap on the right which was only half open at best. I expect it will stop itself but have put a tray underneath for now!
Last edited:
1. Flow should be left to right per your photograph. In to Port A, out from Port B.
2. The drip is probably from the gland nut on the gate valve. Easy enough to stop. Look up "weeping gland nut" or similar on the internet.
3. The gate valve you opened may have been a balancing valve for the hot water system, in which case it should not be fully open.
2. The drip is probably from the gland nut on the gate valve. Easy enough to stop. Look up "weeping gland nut" or similar on the internet.
3. The gate valve you opened may have been a balancing valve for the hot water system, in which case it should not be fully open.
Hi - I can confirm that the flow does indeed go from left to right (the pipes are labelled!)
The drip has stopped already and I have ran the boiler at least 5 or 6 times since yesterdays message so I am happy that its not leaking under hot or cold pipe conditions.
I think (correct me if I am wrong) the balancing valve is the little white dial in the picture below? I've always had all taps other than this one fully opened.
I am still getting the loud bang once the heating finishes. It is definitely coming from the valve pipework. What continues to puzzle me is that by opening the manual lever on the valve, the boiler ignites. I am 95% sure this was not the case in the past - I have notes from the original installation saying to manually open this whenever I need to drain the system (new rads for example) so I am convinced it didn't used to fire when this valve was manually opened. Should it fire when this is opened manually?
I have attached a better picture showing the rest of the pipework around the valve
Thanks as always!
The drip has stopped already and I have ran the boiler at least 5 or 6 times since yesterdays message so I am happy that its not leaking under hot or cold pipe conditions.
I think (correct me if I am wrong) the balancing valve is the little white dial in the picture below? I've always had all taps other than this one fully opened.
I am still getting the loud bang once the heating finishes. It is definitely coming from the valve pipework. What continues to puzzle me is that by opening the manual lever on the valve, the boiler ignites. I am 95% sure this was not the case in the past - I have notes from the original installation saying to manually open this whenever I need to drain the system (new rads for example) so I am convinced it didn't used to fire when this valve was manually opened. Should it fire when this is opened manually?
I have attached a better picture showing the rest of the pipework around the valve
Thanks as always!
1. You are right. The gate valve is there to enable the water to be isolate in order to change the motorised valve. It is not for balancing.
2. The valve at the left of your latest photograph does look like an automatic bypass valve.
3. The drip is likely to be fixable as previously advised.
4. There is a microswitch inside the valve. When the valve operates at the direction of the thermostat, it moves to the open position. As it gets to the end of this movement it closes the microswitch and signals the boiler to fire. Normally the manual lever doesn't move the mechanism far enough to affect the microswitch. Sounds as if yours is doing so however. Doesn't really matter.
2. The valve at the left of your latest photograph does look like an automatic bypass valve.
3. The drip is likely to be fixable as previously advised.
4. There is a microswitch inside the valve. When the valve operates at the direction of the thermostat, it moves to the open position. As it gets to the end of this movement it closes the microswitch and signals the boiler to fire. Normally the manual lever doesn't move the mechanism far enough to affect the microswitch. Sounds as if yours is doing so however. Doesn't really matter.
Final update on this one for anyone else wondering / who looks at this at a later time - the valve was indeed the wrong way round. BG came today and immediately said it was likely to be that. A quick change and it was all resolved. Picture attached!
Needless to say there was no charge involved. The previous person who came was a contractor for BG, he had actually visited twice for the same valve issue. Still didn't get it right it seems. We could go on all day about poor workmanship - its the same in all jobs, not limited to trade or any other job type in particular. I've long held the opinion that 10% of people are good at their jobs, the rest just get by!
Thanks for all those who have commented and given me insight / info
Needless to say there was no charge involved. The previous person who came was a contractor for BG, he had actually visited twice for the same valve issue. Still didn't get it right it seems. We could go on all day about poor workmanship - its the same in all jobs, not limited to trade or any other job type in particular. I've long held the opinion that 10% of people are good at their jobs, the rest just get by!
Thanks for all those who have commented and given me insight / info
DIYnot Local
Staff member
If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Are you a trade or supplier? You can create your listing free at DIYnot Local
Sponsored Links
Similar threads
