I bought my first house in November, in which there was an oil fired Worcester Bosch Combi boiler of indeterminate age. The boiler seemed to be working fine when we moved in, but as a precaution, I had it serviced in early December as it seemed to smell a bit rich when burning. The engineer confirmed that the boiler had, in all likelihood, not been service for a good while as it was burning very inefficiently. After the service, the boiler seems to have has been working much better, and burning far less oil.

Two weekends ago, I bled the bathroom radiator as it was only getting hot about a 1/3rd of the way up. I topped up the pressure in the boiler (1.5bar) and away we went. Since this point, the boiler has been losing pressure over the day to around 0.8bar at which point the thermal cutoff activates.

Upon inspection, I’ve noticed water at the rear of the boiler. Further inspection (panels off) revealed that the insulation around the heatslave tank was sopping wet, and that the upper portion of the tank is HEAVILY (like 3mm thick sections flaking off) corroded.

Has anyone had a similar fault and does anyone know if it’s economically viable to fix?

Difficult to say. Non condensing boilers should last for ages. Worcester Bosch are one of the better makes so spares are likely to be available. The only answer is to get a reliable plumber in, or a Worcester Bosch service engineer to take a look.

Personally I’d probably just bite the bullet and get a new boiler (Worcester Bosch, Grant – something well known).

Rich.

Depends if a replacement part is available. You might not have a choice.

Worcester Bosch employee here, chances are, if its a combi, parts will still be available, give us them a call 🙂

Water jacket or the preheated tank on the side?

Side tank is reasonably easy to replace, water jacket much harder.

It’s the water jacket. There’s a heavy amount of corrosion on the upper and side surfaces, but I haven’t yet removed all of the insulation.

one of these?

https://www.dhsspares.co.uk/product/worcester-87161213680-hs15-19-rso-heat-exchanger-spare-assy-1016913

Think it’s new boiler time!

Worcester have a fixed rate of £266 to repair/replace all parts if viable. Added a service to it for £326 just before Xmas.
Had quite a few bits replaced including the expansion vessel which your problem could be.

I think they key to that sentence is ‘if viable’ that would make them wriggle out of repairing it I would imagine.

Also can’t believe that applies to oil boilers such as this one.

Say I do go down the replace route, does anyone have any clue as to what I should replace it with?

This is my first house and I don’t have much experience with boilers.

It’s a 4 bed, 3 bathroom detached house in an exposed position. The house has no water tank and has an electric and conventional shower. It would have to be oil. I don’t have the space for biomass.

indoor or outdoor boiler ?

I went with grant – got a vortex pro 26 external boiler at mine , its been peachy.

I looked at all the “eco” options , all either required unneccessaryally complex systems to automate it(and i still believe in more shit = more shit to go wrong KISS) or wouldnt provide enough heat for my house which sounds similar to yours – ie ground/air source pumps or were rediculously expensive and the time to break even point exceeded my life time over just using oil.

personally I’d go for a non-combi. Get an indirect tank fitted with a solar coil and fit a couple of wet solar panels when you can afford it.
However, the time you’re expecting to stay there, available space and finances would all impact your decision.
Cheapest option is probably a replacement oil combi.
Rich.