Pressure problems after bleeding rads.

[jimbobaroo2]

Hi all

First time on site and must say its pretty good.

Read a lot on the forum as l now have a problem, but need a more definitive answer if possible from someone with expertice.

Unfortunately l have a Saunier Duval SD30e combi which hasn't been too bad since we had it fitted 6 yrs ago, but the other day l went to bleed the rads with the heating still on ( l know now silly thing to do ) and a lot of air came out of the last bedroom rad , so gave it agood drain.
When l checked the boiler pressure after it was at zero so topped up using the filling loop too about 1.5 bar.

Problem now is since then the boilers been loosing pressure quickly, about 7hours from 1.5 to zero bar, and hence heating goes off.
Also the outside overflow pipe leaks all the time now, where as before it never did.

I'm wondering if l over filled a hot system, opened the pressure relief valve and now its stuck open.

Can any one please shed any light on what the problem might be and how to resolve it. I'm happy to tackle it my self if not too difficult.

Many thanks for any feed back.

Bob.

P.S. I've rang the companys helpline to no avail.

 

[agatto2]

Hi Jimbob

The seat of your relief valve might have a little something caught in it. Check your pressure though, if its around 30 lbs your gonna blow the valve all day long . If your pressure is below 20 then try snapping the safety pressure valve closed to see if it cleans it up (I know its a duh but be careful hot water under pressure does burn)

You might have to bleed the system again, especially when you let in more water.

Your tank/bladder might be full -- in which case you must drain or replace

There is a link on my site that is a must for anyone owning a boiler. Its a free book written by b&g , and tells you everything you need to know about your boilers hydronics. The link can be found at www.furnacebook.com

Hope that helps Tony

 

[jimbobaroo2]

Thanks for that Tony, but how would l snap shut the pressure relief valve ?

Cheers Bob

 

[agatto2]

Hi Bob --- There should be a little silver handle on the brass pressure valve. You can try tapping the middle of that with a hammer, I have done this before. If that does not work ,, put a bucket under the pipe that is attached to the valve ,, or remove that pipe and put a bucket under the valve. Grab that little handle , lift up ,, some water will come out under pressure and hot, so use some gloves. Then just let the little silver handle go , its spring loaded and should snap back into place.

This wont work though if your pressure is getting near 25 lbs. You will have a different problem then. Did you get the download link from my site? Its really handy to have that free hydronic book lying around.

Tony

 

[twgas]

agatto, our pressure gauges on boilers in UK are marked in bars no PSI (1bar=14.5PSI approx)

jimbob, sounds as though your expansion vessel may need recharging, see FAQs.

 

[jimbobaroo2]

Hi guys , thanks for the feedback.

Hopefully will get chance to look at the boiler soon.

If and when the problem is solved will l have to flush the system and refill with inhibitor to replace the pressure/water lost through the PRV ?
The system is 6yrs old and had Sentinol X100 in it before.

Also the pressure drops even when the boiler has been turned of all day.
Does this fact point to any specific fault along with what l've already wrote ?

Cheers , Bob.