Pressure relief valve constantly flowing

TheChizler

In ashamed to say this has been ongoing for months but we had no issues with heating so no incentive to get it sorted.

The pressure relief valve outlet in the boiler in our apartment had been constantly running for a long time now. At first I thought it was possibly condensate but as its getting warmer we're using the boiler less and it's still constantly dripping. I measured the rate today and its losing about half a litre every minute, so I said I need to do something about it!

Clearly pressure, which looks too high up at 2.5 bar when cold, is being maintained by the filling loop inlet valve. I've tried turning/half turning this valve all directions and only succeeded in raising the pressure, it never decreases below 2.5 bar even with the relief valve running like a tap or me bleeding a couple of litres out of a radiator. Does it sound like the inlet is stuck open, or could it be one of those automatic ones that auto fill to a certain pressure? If it is it's surely broken anyway if it's maintaining 2.5, not 1 bar. It has the number 15 stamped on it, 15 PSI, ≈ 1 bar? Or is that the size of the fitting?

Had a plumber out a year ago for a similar thing and he replaced the pressure relief valve, I'm thinking now could the stuck inlet be to blame for that breaking too?

There's a guage by the inlet that I'm trusting for readings, the one in the boiler is stuck at a high value.

Boiler is long due a service so I'll bring that up with this issue when contacting the landlord on Monday, but for my own curiosity what do you think the issue is here?

1874

You look to have water leaking all over that 2nd picture, pipe and fitting, Id be getting that sorted ASAP, 1/2 a litre a minute doesnt sound like a drip,

probably pressure relief valve gone and maybe the expansion vessel, the latter may be the original cause of it all or it could be the filling loop or a combination and including your gauge might need to be checked.
Best way Id say to sort this is turn off the supply loop and see does pressure drop, it should and then dont reuse until problem fixed, you havent just been pouring water away but must have been losing heat too as you'd surely have been expelling heated water, then get in a plumber, depending on your boiler set up, this may need to an rgi.

Sleeper12

TheChizler wrote:

In ashamed to say this has been ongoing for months but we had no issues with heating so no incentive to get it sorted.

When you fill a heating system you fill it with fresh water. Fresh water is corrosive. When you turn the heating on the water oxidises & its no longer corrosive.

The bad news is that you have had fresh water in your heating system for months. Your rads are possibly rusting from the inside out by now. You need to get this fixed ASAP.

TheChizler

The water on the pipe I've confirmed is condensation forming on the inlet pipe thankfully, no leaking at the joints. Probably another sign that there was a constant flow, in hindsight.

That's the problem no matter how I turn the supply loop inlet the flow doesn't seem to stop. Guessing its fecked.

TheChizler

Sleeper12 wrote: »

When you fill a heating system you fill it with fresh water. Fresh water is corrosive. When you turn the heating on the water oxidises & its no longer corrosive.

The bad news is that you have had fresh water in your heating system for months. Your rads are possibly rusting from the inside out by now. You need to get this fixed ASAP.

I was thinking that

Is only today I discovered how fast the flow was, I had noticed a lot of dripping on the outlet a few months ago and said it to the plumber and he said don't worry it's just condensation. Clearly it's not. Also all the neighbouring apartments are exactly the same so I was wondering was it normal for this boiler.

1874

I doubt very much that that is solely condensation, for one you'd have to have a significant source of moisture (so warm air holding water vapor in the air) to condense on a cold surface, wheres that coming from? its not normal, you look to have a leak, not sure why you're insisting thats condensation, for that much water which looks to be dripping down the pipe to condense on a cold pipe??
You need a plumber, probably a different one to the one you got before.

TheChizler

It's not a leak as water would have to be flowing up from the joint, the angle isn't clear from the picture. The other end is a bend so unless it's a pinhole unlikely to be a leak. You can see the condensation forming on the top of the pipe and running down to the bottom where the drops are growing.

Now that means it's very humid in the press and maybe that's cause of a leak elsewhere else, when the boiler's on the flow coming out of the pressure relief is steaming so maybe that's the source?

I'll advise the landlord to use a different plumber though! Thanks for all the thoughts so far!

Sleeper12

The condensation is there because there is a constant flow of cold water entering the pipe. Sort out the pressure relief valve and the condensation will sort itself out

TheChizler

Just had another look outside now that the heating is on, flower beds are steaming and outflow pipe is too hot to touch. Only happened to notice earlier as it was the first day good enough to hang up washing outside, wouldn't use the back "garden" otherwise. Don't want to think about how much hot water's been wasted or the corrosion that's been going on in the system. Organising a plumber ASAP.

Those little black handles for filling should be at right angles to the pipe when they're closed right? Doesn't seem to make a difference which way it's turned I can still hear water flowing through it. There's no visible stopcock for our apartment so I can't even stem the flow there.

1874

As you mentioned this was a rented property by way of saying youd inform your landlord, Id leave well enough alone from now on in, and let the landlord get someone to sort it, as I rented out a place in the past, If it was me, Id be fairly unhappy if someone was messing about with turning valves on/off, leaving the fill loop on and getting their own plumber. The duration this has been going on has probably caused more damage in the long run than a leaking PRV.
If you havent formally reported this, you might end up finding yourself liable if its in your lease, ie knowingly allowing a faulty system to be run continuously, if you have reported it you might be covered, but leaving the fill loop on permanantly is beyond me.

The black handles should be at a right angle but if they arent turning anything if they are broken then they wont do anything, Id be watching out for pin hole leaks, at least with the water off the leak wont be continuous, with a constant supply any leak could start affecting other people (ie you said you were in an apartment?) although your pictures show you have access to ground level? At the least its just causing more damage.
The loss of hot water and what it has cost you, which I highlighted earlier is the least of the problem at this point.

TheChizler

Landlord had told us to bring up the pressure if we need to. We're here nearly 5 years and had to top it up occasionally when the boiler was complaining about low pressure, every 4 months maybe. Was always very easy to adjust, valve worked well and it was possible to set the pressure very finely so it did work at some stage. Haven't needed to since the plumber was at it.

As I said I only realised it was a problem today, hence the thread, I was aware of a dripping but the landlord's plumber said not to worry. We're ground floor all right so no worry about affecting someone else, thought we've had issues with leaks from upstairs, their outflow valve, and the two next door, is constantly flowing too so I'll point that out. Could there be a problem of too much pressure in the complex?

Anyway it'll be in the landlord's hands from now, just wanted to be sure it wasn't anything I was doing. We're on good terms with her any anything that affects her property has been reported as soon as we've noticed it.

TheChizler

Rang the plumber last week and they weren't that concerned, said to use as normal and they'd get back to me. Fast forward to just now and this:

https://www.youtube.com/watch?v=xTcCbTN7uPE

Turned off the power to the boiler and no change. Luckily last weekend I removed the panel in the cupboard under the sink so the mains valve could actually be accessed, in anticipation of the plumber needing to turn off the water, and shutting it off there stopped the noise.

Landlord is trying to find a plumber who can come out urgently as we've no water bar what's in the tank. Not willing to turn the water back on.

What's the likely source of that noise? I'm assuming the pressure relief valve is corroded or fecked from being constantly activated and is reciprocating when the water is on.

DGOBS

Sounds like the pressure relief valve is hammering (opening and closing in fast succession)
Turn off the boiler and close the flow and return valves under the boiler, noise should stop in a minute or less.

Do not turn back on the boiler (as valves are closed) and wait for the plumber.

1874

I thought you were getting that sorted urgently over a week ago :eek:
Thats some racket, I think its giving up the ghost, I reckon just keep doing whatever you're doing, be grand sure run it on :pac:

I didnt know a gas boiler could do that/make noise like that




(edit, Im kidding, get it sorted asap, but actual asap)

TheChizler

DGOBS wrote: »

Sounds like the pressure relief valve is hammering (opening and closing in fast succession)
Turn off the boiler and close the flow and return valves under the boiler, noise should stop in a minute or less.

Do not turn back on the boiler (as valves are closed) and wait for the plumber.

Might do that if the plumber doesn't get here tomorrow, we've no water otherwise! Thanks for the tip!

TheChizler

1874 wrote: »

I thought you were getting that sorted urgently over a week ago :eek:
Thats some racket, I think its giving up the ghost, I reckon just keep doing whatever you're doing, be grand sure run it on :pac:

I didnt know a gas boiler could do that/make noise like that




(edit, Im kidding, get it sorted asap, but actual asap)

I thought the neighbour's washing machine was coming through the floor initially! Mad noisy.

Landlord is happy to categorise this as an emergency so it should be faster getting someone in now. Are plumbers particularly busy at the moment?