Conventional boiler problem

Possibly partially right for some situations! (that got enough get out clauses in it? ;-)

Pipework and TRVs are usually fine at pressure (just think about you mains water pipes etc).

Rads are also usually fine unless on the last legs - in which case the pressure change may push them over the edge and you will get pinhole leaks. However if this is the case they were due to do it anyway - you just accelerated the process by a few months. For a system treated with corrosian inhibitor on a regular basis this ought not happen anyway.

Old lockshield valves may weep when the pressure is increased. Having said that there is no guarentee they will (the ones on my system were fine when I converted it to sealed operation)

Reply to
John Rumm
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Thx John......IIRC the TRV's and the lockshields were fairly new anyway at the time .As for the radiators they seemed /seem ok. What might have been a problem and still would be presumably is that the system is fed from a cold water tank in the communal loft and did at one time serve several other flats ( which had hot water cylinders but now have combis,me being the last one ) so inhibitor isn't used .I know that any time I've removed a rad it has been filled with black muck when I've washed it out and I wouldnt want that getting in to any new boiler if it was only the boiler that was replaced . Powerflush .?????

Stuart .

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Reply to
Stuart

The tank that feeds the hot water cylinders etc would have to be different from the one that serves as a feed and expansion tank for the CH - so that would not preclude use of inhibitor.

One option certainly. Adding a desludging chemical to the existing system a couple of weeks before it is decommisioned might be a good move. Give it all a good flush when the new kit goes in, and fit a strainer to the return to the boiler to catch any dislodged crap before it gets into the new boiler.

Reply to
John Rumm

It's a single feed Primatic I have so the cold water going in from this tank in the attic fills the HW Cylinder and that serves both the CH and DHW ( in my flat anyway as the others ,as I said,have had the cylinders replaced and combis installed ) .The only other pipes connected to the cylinders are the DHW outlet and an expansion vent which goes back up to either the roof or the attic where it is vented back in to the tank..

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Reply to
Stuart

Ah, sorry missed that bit...

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John Rumm

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