powrmatic high level wau

[no1keeper]

Good evening guys(and girls!)....I am new to this forum and i am hoping you can help me?
Today,i had a job attending to a high level warm air unit (powrmatic pgu100).The unit had been previously isolated many weeks ago.The warning sticker on the front of the unit stated a cracked heat exchanger.After removing the front panels,i checked everywhere for the crack.I then did a flue flow test which was fine(no smoke emitting from the heat exchanger at all)....i was then given the last engineers report and it stated that the crack was at the bottom right of the heat exchanger.....after retreiving my torch i saw what was 5-6mm,idescribably thin "crack"....added to which,the crack was on the base of the heat exchanger,where the flame doesn't reach....Was this really worth condemning especially as the flue flow test was fine??

cheers guys

 

[so-solar]

what would happen if the flu became blocked? That is the first thing that entered my head after reading this post!

 

[no1keeper]

what would happen if the flu became blocked? That is the first thing that entered my head after reading this post!

Surely if that happened then the fumes would escape via the burner assembly,as this is an atmospheric heater??

 

[migoplumber]

ID was correct diagnosis.

heat exchanger is part of the flue system and gas integrity. it has failed, and should not be repaired, but replaced.

before replacing, think about the cause. check gas pressures and flame picture, you can use the existing heat ex to make a full check, but remember to leave it isolated and capped afterwards.

 

[no1keeper]

ID was correct diagnosis.

heat exchanger is part of the flue system and gas integrity. it has failed, and should not be repaired, but replaced.

before replacing, think about the cause. check gas pressures and flame picture, you can use the existing heat ex to make a full check, but remember to leave it isolated and capped afterwards.

Ok thanks for that...I did actually reinstate the heater,TEMPORARILY,to check the gas pressures,flame picture burner assembly etc,which all checked out fine?...must be a flaw in the metalwork is all i can think of.
cheers for that

 

[Plucky]

it may have cracked from heat. What happens if you reinstate and crack gets worst after you have left.

 

[Bernie2]

Agree with Migo,

The testers went mental about anything like this regarding warm air.

The problem is, its only a heated chamber, but it blows into every room heated.

And it gets hot in the air chamber so the crack could open up.

 

[migoplumber]

do hope by temporary, you just meant for testing. that you are allowed to do.

if you have left site with the appliance still connected you are totally liable for the bloke that dies, or just decides to report you for the fun of it. you lose your gas ticket for that!!

 

[no1keeper]

do hope by temporary, you just meant for testing. that you are allowed to do.

if you have left site with the appliance still connected you are totally liable for the bloke that dies, or just decides to report you for the fun of it. you lose your gas ticket for that!!

I did mean temporary!!!....appliance was isolated and capped off again ;-)