Just had power flush

[DaveOC]

Hi, I've just had a power flush and filter on my combi system, the pressure drops dramatically, in the morning it's 0.4 I fill it to 1.2 put the heating on after about an half hour it's 2.2 then another half hour when it reaches temp it's 1.5 and then keeps dropping down to 0.4 as it cools down. The pipe work is buried in the floor but I can't see any signs of water. The well known company that done it are coming back on Monday. Is there any advice anyone can give so I know what to say or do as I don't want to be fobbed off. Many Thanks

 

[Harry Bloomfield]

First point would be - check the PRV (pressure release valve) isn't leaking. The pipe will go out through a wall, down a few inches, then end pointing towards the wall. Idea is if too much pressure appears in the system, valve opens and releases the excess pressure. It may have been jammed partially open by the flushing of dirt in the system. Easy way, is to fit a plastic bags over the end of the pipe, held tight in place by an elastic band. If water appears in the bag, the PRV is passing.

 

[DaveOC]

Thanks, I've checked this and no water is passing through ( unfortunately )

 

[denso13]

The well known company that done it are coming back on Monday.

Some terms and conditions will say that certain problems following a powerflush are not covered. Did you sign anything?

 

[kidgreen61]

Exp vessel probably needs re-charging

 

[ianmcd]

if you have access to it? It will have a valve on it, like a car tyre valve - check the pressure on the valve, it should be around 1.5bar. Car tyre gauge will work fine, as will a bike or car tyre pump.

Releasing the tyre valve, their should be no appreciable amount of water should come out of it.

This is poor advice, this is NOT how you check an expansion vessel

 

[polesapart]

Exp vessel probably needs re-charging

+1

This is poor advice, this is NOT how you check an expansion vessel

Also +1


OP, any signs of water having dripped from an open-ended copper pipe on the outside of your house? If your boiler sits on an external wall you'll likely find the pipe a metre or so beneath the flue terminal, perhaps with an elbow or two on it.


See also FAQ 15 on this forums index page.

 

[Harry Bloomfield]

+1


Also +1


OP, any signs of water having dripped from an open-ended copper pipe on the outside of your house? If your boiler sits on an external wall you'll likely find the pipe a metre or so beneath the flue terminal, perhaps with an elbow or two on it.


See also FAQ 15 on this forums index page.

We have already done that and the answer was none..

 

[ianmcd]

Thanks, I've checked this and no water is passing through ( unfortunately )

best way to check is tie a small freezer bag or similar over the outlet of the pipe, they dont always drip all the time, just when the pressure is high, leave the bag on for 24 hours and see if there is any water in it

 

[ianmcd]

We have already done that and the answer was none..

No water was leaking at the time, doesnt mean it isnt leaking when the system pressure rises

 

[Harry Bloomfield]

No water was leaking at the time, doesnt mean it isnt leaking when the system pressure rises

Whilst not disagreeing with you Ian, I responded to the OP with perfectly clear instructions of how to check it and the OP says he has checked it. Both you and the other poster have more or less suggested the very same thing.

In regards to your other highly critical post, where I suggested checking the EV and it's pressure, what I suggested would certainly get the OP working again if that were the root cause of the issue. Having searched for the FAQ you mentioned for checking the EV, I found nothing relevant there - I would suggest that if I am unable to find it, nor will the OP be able to either.

See
FAQ 15

 

[ianmcd]

Having searched for the FAQ you mentioned for checking the EV, I found nothing relevant there - I would suggest that if I am unable to find it, nor will the OP be able to either.

really must try Harder Harry, read the post properly, I never mentioned anything about a FAQ, and if the OP tests the EV the way you suggest , which sadly is the way most do, then the result will be the square root of diddly squat

 

[Harry Bloomfield]

really must try Harder Harry, read the post properly, I never mentioned anything about a FAQ, and if the OP tests the EV the way you suggest , which sadly is the way most do, then the result will be the square root of diddly squat

My apologies - it was polesapart who mentioned going and reading the FAQ.

Two of in in this thread being critical and neither of you have offered the OP any really useful advice, other than be critical of the advice I had already offered him or pointlessly repeat exactly the same advice. Rather than being critical, why not explain how YOU would check and set up the expansion vessel?

 

[ianmcd]

My apologies - it was polesapart who mentioned going and reading the FAQ.

Two of in in this thread being critical and neither of you have offered the OP any really useful advice, other than be critical of the advice I had already offered him or pointlessly repeat exactly the same advice. Rather than being critical, why not explain how YOU would check and set up the expansion vessel?

Quite simply because it has been posted hundreds of times how to properly do it, if anyone including you cant be bothered to go and look for it, then I am not repeating it constantly, how to check an EV and how to wire a hive /nest ? I know I cant be arised looking for the answer I will just start a new post asking the exact same question, then they get the wrong answer as you supplied

 

[ianmcd]

Quite simply because it has been posted hundreds of times how to properly do it, if anyone including you cant be bothered to go and look for it, then I am not repeating it constantly, how to check an EV and how to wire a hive /nest ? I know I cant be arised looking for the answer I will just start a new post asking the exact same question, then they get the wrong answer as you supplied

Harry I have just checked and there is 103 posts on here telling how to correctly do it, and that is only posts with expansion vessel in the post title