[Help] Plumbing advice needed.

[Seagull on the Hill]

I have a pressurised hot water system, heated by an oil boiler.
There's a slow drip from the overflow pipe ( one drip approximately every 20 seconds at the moment but I think it drips more overnight as there's a small puddle on the extension roof in the morning).
I was told the problem could be the pressure vessel adjacent to the hot water tank, so yesterday I fitted a new vessel which was pre loaded to 3.5 bar.
Unfortunately this hasn't solved the issue and the pipe is still dripping.
Can NSC's resident plumbers suggest what might be causing the problem?
Thanks

 

[Tom Hark Preston Park]

Have you tried turning it off and on again?

 

[Seagull on the Hill]

Have you tried turning it off and on again?

Doh, why didn't I think of that?

 

[Seagull on the Hill]

Since my original post, I have been told it might be a problem with the pressure reducing valve or the pressure relief valve.
I live near Horam, any NSC plumbers cover this area?

 

[WATFORD zero]

Probably worth bouncing around 2.30 - 3 pm, just between Lunch and Afternoon Tea

 

[BN9 BHA]

Since my original post, I have been told it might be a problem with the pressure reducing valve or the pressure relief valve.
I live near Horam, any NSC plumbers cover this area?

You will need someone that has the correct qualification to work on unvented (pressurised) hot water storage systems.
I no longer have this qualification as mine as expired, it’s difficult to diagnose the exact problem here without seeing it and doing various tests.

As you have already changed the expansion vessel my advice is to find someone or a company that regularly works on this type of system.

 

[BN9 BHA]

Probably worth bouncing around 2.30 - 3 pm, just between Lunch and Afternoon Tea

Currently on tea break

 

[Seagull on the Hill]

You will need someone that has the correct qualification to work on unvented (pressurised) hot water storage systems.
I no longer have this qualification as mine as expired, it’s difficult to diagnose the exact problem here without seeing it and doing various tests.

As you have already changed the expansion vessel my advice is to find someone or a company that regularly works on this type of system.

Thanks

 

[Rowdey]

3.5 bar may be too much. It should be at 0.2bar below standing pressure. Measure that, drop the pressure/Isolate it and then repressure correctly or else it wont compress when cylinder water expands into it.
Thats not to say the T+P valve isnt faulty.. i had one 90 degree rated unit go on me at 65deg yesterday, just after i'd heated up the whole 180 litre cylinder..

As usual @BN9 BHA is correct, you need someone with a G3 Unvented cert to work on these ( and that includes you changing the EV btw..)

 

[Lady Whistledown]

Can NSC's resident plumbers suggest what might be causing the problem?
Thanks

I'm going to say it's the water.

 

[Seagull on the Hill]

3.5 bar may be too much. It should be at 0.2bar below standing pressure. Measure that, drop the pressure/Isolate it and then repressure correctly or else it wont compress when cylinder water expands into it.
Thats not to say the T+P valve isnt faulty.. i had one 90 degree rated unit go on me at 65deg yesterday, just after i'd heated up the whole 180 litre cylinder..

As usual @BN9 BHA is correct, you need someone with a G3 Unvented cert to work on these ( and that includes you changing the EV btw..)

Thanks. I looked online regarding changing the EV and all the advice was "This is something that a competent diyer can do" , so I just went ahead.

 

[Rowdey]

Thanks. I looked online regarding changing the EV and all the advice was "This is something that a competent diyer can do" , so I just went ahead.

If you wan to get ahead of an engineer and order part for him to install ( rather than him order it/have to return) then order here - they also do a part search via Whatsapp. - https://www.unventedcomponentseurope.com/pressure-temperature-relief-valves/ - HTH

 

[Bry Nylon]

My standard operating procedure for an event like this would be to simply stop looking at the conservatory roof and hey presto, the problem no longer exists.

 

[BN9 BHA]

My standard operating procedure for an event like this would be to simply stop looking at the conservatory roof and hey presto, the problem no longer exists.

Or seeing as the weather has been so dry, why not attach a hose to the pipe and the other end into a watering can

 

[clapham_gull]

I have an oil boiler in my parents house and frankly wouldn't go near it. I might as well be doing an MOT on a steam engine.

There are a very good company I've used for YEARS who are oil central heating specialists in Heathfield.

PM sent

 

[clapham_gull]

3.5 bar may be too much. It should be at 0.2bar below standing pressure. Measure that, drop the pressure/Isolate it and then repressure correctly or else it wont compress when cylinder water expands into it.
Thats not to say the T+P valve isnt faulty.. i had one 90 degree rated unit go on me at 65deg yesterday, just after i'd heated up the whole 180 litre cylinder..

As usual @BN9 BHA is correct, you need someone with a G3 Unvented cert to work on these ( and that includes you changing the EV btw..)

Saved me from posting it