Pressure issues, help needed please!

[baronwills]

Hi folks

Hoping you can help. I have a customer with a Worcester 30si combi and we have an ongoing pressure problem that i am trying to resolve. From 1 bar cold, switch the heating on and within about half an hour the pressure has reached 3 bar and prv is discharging. I originally thought it was a sludge issue so i drained, flushed and ran a cleanser through the system. This worked for a while but is now back with the same problem.

The expansion vessel and pump are ok. Could this be a sludge issue within the heat exchanger? Phoned Worcester technical and they said it could be but there is no way of testing it.

Any advice greatly received. Thanks in advance.

 

[acecharly]

Possible blockage to expansion vessel or filling loop passing.

 

[baronwills]

Forgot to say, filling loop not letting by. Is there a way of testing expansion vessel?

 

[Centralheatking]

For the pressure to go up like that then the pressure vessel is not operating properly -
the prv is just doin its job. U say the exp vessel is ok - u sure its not full of water
or the air bubble has shrunk so there is nothing to absorb the increase in volume of the hotter cen heating water. take off filling loop to check ace's idea above.

centralheatking - let us all know how you get on

 

[acecharly]

Didnt you say the vessel and pump are ok?

To test it you need to press the valve that looks like a tyre valve on it if you hear a hiss of air its ok if water comes out the membrane has perished so that the pressure has nowhere to go.

 

[baronwills]

I pressed the schraeder valve, had a hiss of air, no water. Re-pressurised expansion vessel. Is there any other sympton that could indicate a vessel problem?

 

[acecharly]

If the pressure vessel itself had a blockage so the was no pressure getting to the vessel.

 

[baronwills]

If the pressure vessel itself had a blockage so the was no pressure getting to the vessel.

So is the only way to prove it by replacing the vessel?

 

[acecharly]

You need to disconect it and check there is no blockage. If it needs replacing i along with many others on here will wish you all the best as its not the easiest of jobs on these boilers the other option is to put another expansion vessel somewhere else in the line.

My advice from here on would be to get somebody in.

The procedure for replacement of the vessel itself will require you to be Gas safe registered anyway.

There is a section on here to ask for an engineer im sure there will be someone close by who can take a look for you if you like.

 

[baronwills]

I am gas safe registered. Dont do many breakdowns though. I can change the expansion vessel if i can be 100% sure thats the issue.

 

[acecharly]

Without being there i hope you can appreciate its difficult. The problem you have is expansion, so the vessel is obviously not doing the job its intended for.

I dont see any other possibility other than a faulty vessel or that it is blocked, so going on the info you have provided id change it or as said put another somewhere in the line.

 

[baronwills]

ok thanks acecharly, will look into replacement.

 

[Nas]

make sure the pipe going to the ex vessel is not blocked. The exp vessel cant do its job if this pipe is blocked

 

[Destroyer2813]

^^ as above check the small metal hose isnt blocked, just cos you have air in vessel dont mean its right pressure bye a tyre pressure gauge to confirm what vessel pressure is

 

[Millsy 82]

Are you sure you have checked the expansion vessel correctly.

 

[Solarbear]

What is pressure vessel reading on pressure tester?

 

[Centralheatking]

Well thought out - acecharly- I have not been on the forum 4 a few days and went checkin whats gone on about things I have had input to so I looked at this one and b 4 I readur post got there as well - what do all the rest of u think - I see no problems

Im all 4 saving dosh myself

centralheatking

You need to disconect it and check there is no blockage. If it needs replacing i along with many others on here will wish you all the best as its not the easiest of jobs on these boilers the other option is to put another expansion vessel somewhere else in the line.

My advice from here on would be to get somebody in.

The procedure for replacement of the vessel itself will require you to be Gas safe registered anyway.

There is a section on here to ask for an engineer im sure there will be someone close by who can take a look for you if you like.

 

[vern]

Blocked at pump housing.......next!