main 24 he

[gigz]

Called out today to finish off a job (plumber been payed and scarpered) after finishing the work (he'd never blanked off pipes, flue was sticking out the wall 500mm as was PRV discharge pipe, condense terminated under workbench, proper cowboy ) Fired boiler up on ch/hw turned on tap working pressure on gas ok, pump bled and working, diverter working. Turned off tap, flame modulated to low for approx 20 seconds then went out. 6 in of the return pipe is hot and does'nt cool down and pump seems to get extra hot and stays running (does'nt seem to be circulating the water). Going back monday (tennant not yet moved in) any ideas appreciated

 

[Paul Barker]

It's probably just heating up a thermal store of dhw, maybe in the expansion vessel or maybe just the water in the dhw heat exchanger itself.

Only othertime a boiler gets hot up the return pipe is when the dhw fglow switch sticks so that the boiler thinks dhw is being called for and fires up, the main symptom apart from a very hot return pipe is that the boiler won't respond to demands for central heating (because combis always give priority to hot water).

The other day I came to yet another boiler with no exit pipe connected to the prv. This was very common on those old worcester combis which had the prv on top, I don't think the installers back then were acquainted with prv's. This last one was a Linea24, but being an lpg boiler and having a multitude of other installations faults, illegal flue position, no drain off on the system (but that's so common it isn't worth mentioning) no time or temperature control, permanent connexion to the water supply using a pressure regulator (and that with no external prv pipe), and gas pressure way off.

I suppose there aren't any corgi registered people in Port Mulgrave.

 

[Slugbabydotcom]

Called out today to finish off a job (plumber been payed and scarpered) after finishing the work (he'd never blanked off pipes, flue was sticking out the wall 500mm as was PRV discharge pipe, condense terminated under workbench, proper cowboy ) Fired boiler up on ch/hw turned on tap working pressure on gas ok, pump bled and working, diverter working. Turned off tap, flame modulated to low for approx 20 seconds then went out. 6 in of the return pipe is hot and does'nt cool down and pump seems to get extra hot and stays running (does'nt seem to be circulating the water). Going back monday (tennant not yet moved in) any ideas appreciated

Funnily enough I am off up your way tomorrow to look at a Main 24 but without the HE which had a similar list of faults when I first clapped eyes on it. Very similar story too about the 'plumber' that got paid and didn't finish the job. I wonder if it's the same cowboy?

Got called back to it 3 weeks after sorting out most of the stuff including nine leaks and found it had tripped on overheat. Reset the OH stat and then discovered that the flow and return valves were on the wrong way! The one with the 1/2" cap on it for the filling loop belongs on the right but was fitted on the left.
It has a filter in it which was blocked with crud from an unflushed system giving the effect of turning the Flow valve off. This could be relevant to your job.
So I am going back half expecting to find that the Secondary heat exchanger is crudded up. All will be revealed hopefully

 

[gigz]

Cheers for that lads i'll see whats in store on monday. tenant said he's payed for a power flush and that cowboy changed rad valves and connected a hose from bathroom tap to rad. Proper powerflush there then

 

[chrishutt]

tenant said he's payed for a power flush

Why was the tenant paying rather than the Landlord?

 

[Agile]

Its very odd. About 50% of that type of boiler I see have the return filter fitted on the left instead of the right.

The most common cause of no CH on that model is a blocked filter.

Setting the min/max and CH settings is important too otherwise incorect operation amd or lockouts can occur.

Tony

 

[cross thread]

pump proving micro switch sticking?