Leak under Heat Exchanger (boiler)

[Frankieboy231]

Hi, I have a Worcester Heatslave 26/32 oil fired combi working well for 20 years (apart from odds and sods over the years)

Now got water leak on floor under r/h side of main heat exchanger (boiler). Checked every joint - all dry and dusty, every entrance to boiler - 3 at front, 2 at back r/h checked and dry.

2 days ago found pool of water under r/h side of boiler with pressure at zero. Topped up water to 1 bar and fired up. All ok with HW but when CH, water leak starts until back to almost zero. Currently working on HW and CH but on atmospheric pressure only. (I know - not the thing to do, but it's cold and all the safety's work). When leak occurs - always under R/H side of boiler (but no joints on that side). Insulation wrapping shows no signs of dampness anywhere. My local plumber suggesting boiler itself rusted through but since this is built from 1/4 inch plate steel (similar to Titanic plumbing) very dubious at spending £6k (suggested price) without finding leak first.

Has anyone had this problem before? Does anyone recognise the symptoms? I can't be the first person to have this.

Currently sitting there with all panels off - just found slow drip at back r/h corner - both joints above dry.

 

[martygturner]

If its gravity fed then the back top right connection is for the return to the tank.

 

[Frankieboy231]

Mains pressure. Entry at top right blanked off.

Any idea if there's any other possible leak points underneath the insulation on the back?

 

[Frankieboy231]

Just looked again at R/H bottom entry (currently fitted with drain) with mirror - welding around back of joint to boiler has lime starting halfway up join to boiler so indication is joint failing.

Question - can this be re-welded? (if welder can ever get to it)

 

[jurassic sparkk]

Currently sitting there with all panels off - just found slow drip at back r/h corner - both joints above dry.

You should not be opening the boiler.

 

[denso13]

You should not be opening the boiler.

Why?

 

[Exedon]

Very common problem we replace at least one worcester combi a month often more.
Normally heat store goes first.
I've welded oil boilers in past where leak is easily accessed if you can't get at it I wouldn't bother.

 

[Frankieboy231]

Very common problem we replace at least one worcester combi a month often more.
Normally heat store goes first.
I've welded oil boilers in past where leak is easily accessed if you can't get at it I wouldn't bother.

Obviously know Worcester combi's. It's a tiny leak from the 'flange weld'. Can this be welded with arc - does it need special rods?

 

[Frankieboy231]

You should not be opening the boiler.

How could I check the pressure without opening a panel?

 

[ianmcd]

Topped up water to 1 bar and fired up

If its gravity fed then the back top right connection is for the return to the tank.

It is a sealed system

 

[Exedon]

If you can get at it any welding method you like will do its just mild steel.
They do have a nasty habit of leaking elsewhere fairly quickly.

 

[Frankieboy231]

If you can get at it any welding method you like will do its just mild steel.
They do have a nasty habit of leaking elsewhere fairly quickly.

OK, Ta for that. So Plumbers Mait won't work then OK, cupboards coming out tomorrow.

 

[Frankieboy231]

Thanks all .........

 

[jurassic sparkk]

Why?

Aren't the corgis only allowed to remove the case?

 

[Frankieboy231]

Aren't the corgis only allowed to remove the case?

I'm not touching the oil-fired bit, only the exterior of the primary heat exchanger (boiler bit) but thanks for caring.. : )