Pressure Loss on Boiler

[K-Rod]

Hi,

I know absolutely nothing about boilers/plumbing so any help (simplified) is greatly appreciated. I thought I'd try you guys before spending a month's wages employing a plumber

Firstly, the answers to the required questions:

1) Boiler make / model (gas or oil)
Gas Ferroli Optima
2) What is / is not happening.
Overnight, when the heating is off the pressure drops to 0 bar, hence no heating in the morning.
3) Has ANYTHING else been done or changed recently.
No.
4) When did the problem start?
This happened a couple of times a loooong time ago but months apart, however it now occurs on almost a daily basis and has done for about 2 weeks.
5) When does it happen? eg, heating coming on or going off.
The boiler is used for water and heating. The problem happens overnight when the heating is timed to be off (off at 11pm, on at 5am).
6) Anything else you feel may be of relevance.
The heating will not automatically come on at 5am until I turn a switch that re-pressurizes the boiler. This affects both heat and water.

If anyone has come across this problem before or if anyone can make any suggestions as to what it could be I'd be most grateful.

Kind regards.

 

[twgas]

does pressure rise quite quickly (from 1bar) when heating is tuned on?
if yes probably pressure vessel charge prob, see FAQ

if not its either a leak somewhere or PRV is passing-check discharge pipe outside

 

[K-Rod]

Hi twgas,

Thanks for the quick response.

When the heating comes on, the pressure goes up possibly a quarter of a bar, no further.

With regards to the PRV pipe, am I looking for a lot of water coming out, i.e. a stream or constant drip etc? Will it only be discharging when the heating is on or will it be all the time? What is the norm for this pipe?

As for leaks, I've had a look round and can't see anything. Downstairs is all laminate floor so I would expect a puddle unless it's under the floor. I can't see any damp spots on the ceilings indicating a leak upstairs. Any ideas?

Thanks everyone.

 

[twgas]

its not "normal" for any water to come out of the discharge pipe, try tying a plastic bag over the end of pipe overnight, this will tell you if thats your problem

 

[K-Rod]

Great idea Mick.

Thanks, I'll be back on tomorrow with any findings!

 

[K-Rod]

Hi Mick/everyone.

In the plastic bag this morning there was approximately a teaspoon worth of water. All comments/suggestions/advice appreciated.

 

[K-Rod]

Hi,

Please can anyone comment on my last post?

I've checked the pipe a few times and it does appear that water is dripping out of it regularly, today it was like a dripping tap! I've also noticed a wet, grey coloured patch on the floor directly beneath the pipe so it looks like it's been dripping for a while.

Does this new info point anyone in the direction of the problem and can anyone suggest a possible fix please?

Thanks as always.

 

[undercover]

Looks as if it needs a new pressure release valve.

However, also need to find out why its leaked in the first place. May be just grit/muck on the prv seal.

When whoever changes the prv, get them to also check the expansion vessel.

 

[K-Rod]

Thanks Undercover.