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Andrew Smith
Andrew Smith, Plumber
Category: Plumbing
Satisfied Customers: 3756
Experience:  City and Guilds qualified plumber
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Hi, Im having a problem with my boiler, its a Caradon ideal

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I'm having a problem with my boiler, it's a Caradon ideal mini s24. There is a constant drip of water coming from the discharge pipe and quite annoyingly this pipe doesn't end over a drain, it ends on an enclosed balcony which fills with about 10cm of water until it overflows.

Anyway back to the boiler, it seems to drip water at all times whether the boiler is on or not although the dripping seems quicker when the boiler is on. The system holds a constant pressure of about 2 bar which doesn't really change if the system is running or if it's been left off for a few days. I gather the safety valve connected to the discharge pipe is supposed to release pressure above 3 bar. So I'm guessing the safety valve is faulty or maybe stuck open.

Can anyone shed any light on this? I know part of the answer will most likely be call a registered gas installer to have a look and sort it, which I will of course do but I would like to know what the problem most likely is before I call so I can speed this up the fix as much as possible.

Any opinions would be appreciated,

XXXXX XXXXX : It sounds like your PRV is faulty, as
XXXXX XXXXX : like you said it should hold 3 bar
XXXXX XXXXX : But it may point to another problem - where is the water coming from if the pressure is not dr4op
XXXXX XXXXX : *dropping
XXXXX XXXXX : You may have a passing filling loop which is constantly filling the system
XXXXX XXXXX : It used to hold 3 bar, but can now only hold 2 bar, hence the constant drip
XXXXX XXXXX : Can you disconnect the filling loop and see if it drips constantly and the pressure drops on the boiler?

Sorry for the delay, electricity just cut out for a few minutes in the whole apartment complex so internet went down. I was assuming the system was designed to fill itself if the volume drops. So you're saying maybe it's filling constantly + a safety valve which can't handle its full 3 bar pressure anymore may be causing the drip?


By disconnect the filling loop do you mean just turn off the valve that allows water into the system?

XXXXX XXXXX : Turn off both ends and disconnect entirely
XXXXX XXXXX : We need to see if it drips when off

I can't see any valve to turn off the water, only the ones for the gas so I suppose I'll have to call someone out to have a look, still thanks for the help. Just one last question, I dusted off the safety release valve, it says 3 bar on top and has an arrow drawn suggesting it can be turned, it also seems loose. Can these safety valves be unscrewed or opened by turning this part on top?

XXXXX XXXXX : You have to swap the whole thing to replace it, you can twist it to release pressure but it may not reseat correctly
XXXXX XXXXX : Do you have a silver flexible filling loop attached to the pipework under the boiler?

I checked pictures of a filling loop online and there is nothing like that. All of the pipes are solid copper, they come out of the concrete underneath and straight into the boiler

XXXXX XXXXX : Page 10 of the manual shows that there is an external one to be fitted
XXXXX XXXXX :,28,32%20Manual.pdf
XXXXX XXXXX : If you cannot see one, can you see where one might be connected?
XXXXX XXXXX : Just the valves left?

No I can't see anywhere a filling loop could be connected. While I was in close to the boiler and pipes I could hear a slight sound of water moving through a pipe. It seems to be coming from that valve connected to the discharge pipe leading outside

XXXXX XXXXX : ok, it may be in the airing cupboard but it must be in sight of the pressure gauge......
XXXXX XXXXX : unless there is an additional one fitted somewhere?

The whole boiler is in a small cuboard, the the gas and water pipes feeding into it from below are all visible. They're coming up from a concrete floor, below this is another apartment and behind this is another apartment. So I cant see anywhere in or around the boiler that looks like a filling loop could be connected to it.


There is the hotpress with the how water tank in it, maybe there's something there

XXXXX XXXXX : it could be anywhere on the heating system

There is still nothing resembling a filling loop or connector in the hotpress but there are valves with red handles

XXXXX XXXXX : Linking the cold water main to the heating?

Yep this seems to be where the mains water enters the system

XXXXX XXXXX : I hope not as red handled gate valves are not guaranteed to shut off against mains pressure
XXXXX XXXXX : Are you able to disconnect or have they broken another water bylaw and piped it in copper?

These apartments were thrown up during the boom years, nothing like that would surprise me

XXXXX XXXXX : Ok, 2 things for the plumber -
XXXXX XXXXX : 1. Replace the PRV

Yep all pipes entering and leaving are copper


Yep, cheers

XXXXX XXXXX : 2. Repipe the filling point as per the manufacturer's instructions
XXXXX XXXXX : This can then be disconnected when not needed

So I can easily shut off water coming into the boiler? Thanks

XXXXX XXXXX : At least you can get a price over the phone before anyone comes out to you and charge you what they want!

That was why I wanted some sort of idea what the problem was first, cheers

XXXXX XXXXX : No problem.
XXXXX XXXXX : Well found, good luck
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