Potterton Profile 80E boiler will not light.

[meec]

Hi all, today I attempted to complete my annual central heating system clean before winter sets in. The cleaning agent circulated for the last few before being drained today. My problem is that since I refilled the system the boiler will not light. My first thought was that I have an airlock in the boiler which is preventing a flow. So using a couple of new fittings and a length of 15 mm plastic pipe I had in the garage, I backflushed the system from the the outside drain point via my garden tap. I let it run through the overflow from the header tank for a few minutes before stopping. Still no joy. Does anyone have any ideas? Al

[Ed Sirett]

Does the boiler appear completely dead? If so the Overheat cut out has probably operated. Reset by pushing it up (it's found underneath the boiler at the front RHS).

This probably tripped because there was no primary flow due to an air lock in the pump or something on those lines.

[<me9]

What on earth were you cleaning? The liquid in my system has been there (give or take a litre or two for 13 years without a problem. When I changed a radiator[*] last year the system (and inhibitor) were in good condition and the radiator contained negligible sediment.

[*] Changed for larger one, as SWMBO didn't like the design temperature, and required the bedroom to be maintained at 20C.

[Dave Plowman (News)]

Could I ask why you do an annual clean? Changing the inhibitor every few years coinciding with new TRVs etc yes, but cleaning? Nothing should be in there to contaminate things. And in a hard water area all you're doing is introducing more crud.

[meec]

Ed, yep that is what it was. All is now well after resetting the overheat. Thanks very much.

Al