Spillage on inside of case (Worcester Greenstar 24i System, 2001)

[cr0ft]

Went to this boiler today to service for the first time and found black spillage marks all over the inside of the outer case (mostly inside the airbox seal area but not all, some are clearly visible outside the seal).

Noticed there is a case screw missing on bottom left so am going to replace that and the airbox seal. Anything else obvious to look at? Combustion analysis readings are all within acceptable limits.

Is this common for these boilers? Never seen it myself before.

 

[ShaunCorbs]

common heat damage, i would say 8-10 years old?

 

[Last Plumber]

It's just heat and dust by the look of it.

 

[Scott_D]

Has it got the kebab HX?

 

[quality]

If that was spillage it would be black bright (pardon the pun)

 

[townfanjon]

Another one for heat / dust

 

[cr0ft]

On closer inspection the case is missing one of the retaining screws on the bottom left (couldn't see it till I came to put it back on, hidden by boxing) and it's not sealing properly onto the air box. Going to replace the case screw and fit a new seal just to be safe, both cheap parts. Cheers all.

 

[cr0ft]

Has it got the kebab HX?

Yes.

 

[Vee]

Watch out for a failed burner gasket (red) at the top of the heat exchanger. Even if the values are fine this could be leaking. There is a recommendation from Worcester to change these periodically, bit like the circular one on Vaillant. Not sure of the interval.
By the time it’s leaking fully you could get total meltdown on the other plastics particularly the fan. (Expensive)

 

[cr0ft]

Thanks mate

 

[sammathias]

Did you fga it with the case on tho?

 

[cr0ft]

Yes, 10.3% CO and 0.002 with 125 parts CO on max rate.

Ratio down to 0.0005 with new Case seal so something was going on for sure.

 

[Starky]

Another one for heat and dust. Used to see this on old isars and icos boilers.

 

[masons]

these combustion boxes are not sealed anyway look in the 4 corner at the back , anyway probably time to change the read seal judging by the amount of staining there and that IS NOT a normal/common amount of black marks/staining within the worcester ( especially system boiler ) and while your at it i expect the heat exchanger could do with cleaning with constant over gassing , you can tell by measuring the fan pressures if it does , but the gas valve on these constantly change from year to year so need adjusting every service probably . probably see about 600 - 800 of these boilers a year