glowworm 24cxi problem please advise

[Reeves2k2]

Recently had to drain the system a couple of times to fit a new rad after a bathroom refurb

Friday night I drained down and refilled but noticed it took longer than usual to re fill and pressurise (From the filling loop)

Anyway I got it to 1.5 bar and run the heating up then bled the rads and topped back up to 1.5 bar

I noticed later Friday that The pressure had risen to 4.6 bar and boiler locked out so I reduced the pressure back down but noticed that the overflow? Copper pipe outside was dripping (which I assumed was normal as the pressure was high)

Yesterday afternoon the pressure dropped and locked out at 0.5bar
so I completely drained down again what was left in the system and re did the whole procedure but have noticed that the overflow pipe just drips constantly outside now.

I am after a bit of advice on the issue as I assume the pressure will now drop slowly as the overflow is dripping constantly

From the mimirage of internet sites it seems to point in the direction of the expansion vessel may need re pressurising or the pressure valve being faulty and not closing after being open

I must add I am not a plumber but am a very competent diyer and can tackle most things but I need to gauge whether it is something straightforward that I can tackle or if I need to get a plumber in
as we know plumbers aren't cheap which is why I would be reluctant to pay if it is a simple thing but if it does need it I have no problem getting somebody in

 

[jackthom]

Hi it does seem the expansion vessel is not doing it's job properly and as a result of excessive pressure the release valve (PRV) can also become stuck in the open position.

Some good information from the FAQs here..

//www.diynot.com/forums/plumbing/faqs.37170/#251090

 

[Reeves2k2]

Thanks for the quick reply

You don't happen to know how easy it is to access the vessel on this boiler to check the ppressure do you?

Also if the prv hasn't closed properly is it possible to make it close itself or is it a case of a new part?

 

[Aquaheat]

Easy enough to get to the shraeder valve. Behind the boiler, top rear.

Make sure you have 0 pressure in the system and check vessel pressure. Should be 1 bar. If not repressurise. If this isn't possible then the vessel may be faulty.

You also state that your system hit over 4.5 bar! This is cause for concern and I would definitely be looking at replacing the PRV regardless. This should activate at around 3 bar anyway.

It may be worth checking your pressure gauge is actually accurate. You did mention that it took longer to reach 1.5 bar than normal. If the gauge was faulty you may have put too much pressure in in the first instance.

 

[Agile]

I think that you have a digital pressure display?

If so then its very likely that the pressure sensor is partly blocked and will take a while to respond so quite likely you over pressurised it yourself.

Best to just set to 1.0 bar and watch it for a few minutes to see if it increases.

Fairly easy to repressurise the air side of the EXV. But it really needs to be done very correctly. Unfortunately the FAQ are not very well written and I would like to rewrite them but don't have editing rights.

Tony

 

[Aquaheat]

You are right Tony it is digital 😳 the issue still remains, as you say it could be a blockage or faulty sensor.

I would say faulty at a guess as it seems to be both under and over reading according to the OP.

 

[Reeves2k2]

Thanks fellas
it did take longer than usual

Never had that problem before and it seems to be working ok with the pressurising reading now

But that aside you mention the faqs were a bit vague
I don't suppose you could give me a bit more detailed instructions?

As I'm going to try the cheapest first and go through that way

The pressure has stayed at 1.5 bar since yesterday but I still have this steady drip from the overflow pipe

 

[Agile]

I am sorry but whilst I am quite prepared to rewrite the instructions for the FAQ where they can be used over again unfortunately I am not going to do it more than once.

It is surprisingly long a task to write it as it needs to be carefully thought about to ensure that it cannot be misinterpreted.

Boilers don't have "overflow" they have pressure release valve vents!

Tony

 

[Reeves2k2]

I am sorry but whilst I am quite prepared to rewrite the instructions for the FAQ where they can be used over again unfortunately I am not going to do it more than once.

It is surprisingly long a task to write it as it needs to be carefully thought about to ensure that it cannot be misinterpreted.

Boilers don't have "overflow" they have pressure release valve vents!

Tony

No problem

Thanks anyway

 

[Agile]

Sorry, but I really would like to help everyone on an ongoing basis, but if the site management don't want to give me the opportunity then it will not happen.

Tony

 

[Reeves2k2]

Sorry, but I really would like to help everyone on an ongoing basis, but if the site management don't want to give me the opportunity then it will not happen.

Tony

It a not a problem buddy
I understand where your coming from

I would be of the same thinking it would get very tedious writing the same thing over again when it could just be updated in the faqs and stickied for everyone to see