Rusted Old Boiler

danjo-xx

Grant Multipass 70-90 running great and think a new burner was fitted at some stage but the boiler casing round flue is very rusted and the brass vent yoke keeps spilling out water which may have caused the rust round flue.

Pointed this out during a service but no help was offered in solving the leak.

On the face of it does the boiler unit look bad or on its way out!

Getting a service soon from a registered contractor and will ask him for a full report and hopefully to sort out the probelm.

What do ye guys think going by the pic's so I can have some bit of an idea what to expect and not be told ~ new boiler if un-necessary.

Billy Bunting

The Brass "yoke" is an Automatic air vent, not an expensive item, you should point out that this needs changing when booking your boiler service as this isn't normally part of the service and will require more time if the Engineer needs to drain the system.
Can't really see much from your picture but from what i do see the boiler doesnt look too bad.

DoneDL

Have to agree with Billy, might be worth putting some hammerite on the rusted areas to to add some protection and the Air Release Valve will show the water quality of the heating system.

aujopimur

It looks like it's just rust on the casing, for cheap fix use metal ( you might get away with a plastic one) car or cycle valve cap and a bit of thread tape to replace the little cap on the auto air vent.

DGOBS

the auto air vent should be replaced, ignore the cap and tape cowboy approach, the vent should be left open to release any trapped air at the boilers high point (thats why the manufacturer wanted one there!)

As for the rust around the flue, looks like someone has sealed it all nicely with some high temperature silicone, the rusting there most likely occurred in the past where flue gas was leaking there (it's corrosive) and the hammerite sugestion is not a bad one, but make sure it cures well before trying to fire the boiler, and check with the instructions that is can withstand 200+ temperature (as your flue gas will be 210-220 degs)

Stove Fan

Is it a balanced flue? Ie terminating outside with two pipes inside each other or goes vertically once through the wall?

Is it my imagination or does the flue slope upwards from the elbow?

If this is a balanced flue driving rain could get inside and run out where it has now been sealed. The block mortar joins look damp around the flue.

If it is a balanced flue it should slope down very slightly to combat this.

If it's a flue thats vertical (open flued) make sure there is a hat on the top to stop rain coming down.

Stove Fan:)

DGOBS

Thats a single walled, single flue pipe, most likely with a low level discharge, also eing a grant mutilpass the flue terminal will be the one with the blanked end and holes around the end terminal (no rain cap required) and this flue terminal could well be source of the damp mortar joints due to condensation of fluegas on the wall at the terminal (most were never extended far enough from the wall)

If there was water ingress via the flue it would be more evident in the boiler than on the outer casing (unless it is leaking)

BOILER FAN

danjo-xx

thanks a mill guys some excellent advice and much appreciated I'll come back to this shortly.



Meantime have a related problem which is very urgent with winter approaching and think I'll start a separate thread on it. 'Pitching'