Pressure problem??

[Bluesbreaker]

Hi all

First post, so please be gentle if i'm a bit wet behind the ears.

I have just moved into a house with a Worcester 28Si II combi, which was fitted four years ago and has been regularly servced by British Gas. It appears to work fine - the hot water output is good and the radiatoras all heat up.

However, I have noticed a problem with the pressure and the manual doesn't help in the least. When I moved in, the pressure was around 1 bar when idle and 1.5 with heating on. Two days later, this had dropped to around 0.3 bar with heating on and virtually zero when idle. I followed the instructions for the filling loop and replenished the system. I have had to do this at least three times a week - seems to be more on the weekends when I use it more.

All joints and valves appear to be dry and I can't see any evidence of water leaking onto the downstairs ceilings from concealed pipes. What could be the cause of this dropin pressure? It's a bit of a worry as it just doesn't stand to reason - where's it all going?

Any advice gratfully received

 

[andytheplumber]

You have a leak. Or pressure relief valve is dripping.

 

[kev_1911]

check outside where the boiler flu outlet is,you will see a copper pipe poking through the wall and it should be angled back towards the wall,as andy says if its dripping then you need the prv replacing,if not then you need to look under your downstairs floors for a leak.

 

[Gasguru]

The previous owners clearly had a problem with the system.

If they have been filling the system as you have the system could be in a very poor state (ie corroding).

Did they say the heating system was in good order on the questionaire..if so get your solicitor to advise. I've seen too many homeowners stitched up by vendors lying about the state of the services.

 

[Bluesbreaker]

I had feared as much. The vendor claimed it was in good working order and he did have a little wadge of receiepts from British Gas to say they'd replaced some basic parts and serviced the system in December 2007, 2006, and 2005. The boiler was only fitted in 2004.

I fear I may have to rip up some lovely flooring to try and find this leak, but it has to be done, I suppose. Are there any clever tricks heating engineers have for establishing what part of the system is leaking, or is it complete guesswork?

Thanks for the replies.

 

[Agile]

Heating engineers always carefully examine the boiler first for internal leaks!

Tony

 

[kev_1911]

steady now before you get the crow bar out,first of all check if you have a hatch where you can gain access to the crawl space under the floors,also if its only a small drip of a leak then you could try a leak sealer additive before you go demolishing your lovely floorboards,but if this fails then its the more harsh method i'm affraid.

 

[Bluesbreaker]

Thanks Kev and Andytheplumber. I checked the pipe and although there was no evidence of drips on the wall, when I touched the end of the pipe it let out enough of a dribble to create some drips on my hand. I checked after the boiler had been in use for a while and it was the same. Would you say this means there's a problem with the relief valve? Or is this type of drip normal?

 

[Bahco]

Read this

 

[Bluesbreaker]

I have spoken briefly to the engineer, who has basically lost interest in helping me. I told him that the PRV outlet on the external wall contains water but doesn't seem to visibly drip. If I tap my finger over the end of the pipe, I get a wet sleeve pretty much every time. To me, this doesn't equate to the amount of water I am topping the system up with, but i'm clutching at straws before I have to rip my home apart trying to find a leak that I might not be able to find anyway. I am obviously quite perturbed by the very prospect.

How much water in the PRV outlet is too much, if you know what I mean?

Thanks

 

[kevplumb]

How much water in the PRV outlet is too much, if you know what I mean?

any