Is Grundfos ups 15-50 man enough for 15 year old 4 bed detached 8mm Microbore CH system

[IMM]

Using the correct inhibitor lubricates as well, reducing this sort of thing.

[Andy Hall]

Well.... you wouldn't want to pressure wash it in your living room, would you ;-). That would remind me of the way that Mr Bean does the decorating.

.andy

To email, substitute .nospam with .gl

[Moonshine]

OK I've checked with the neighbour and their's is the Grundfos UPS 15-50 too, so my memory is obviously playing up and it was in the last house that I must have changed it! So hopefully it has been properly spec'd for the job.

Also confirmed that their's is set on max speed, and I would imagine they wouldn't have tinkered with it like me :-)

I've done some more research on the Valve and its a Honeywell V4073A Motorised Mid-Position Valve. Which according to the spec sheet does only have between

10&15 degrees of spindle movement.

I haven't got my thermometer at the moment, but I could swear since giving the spindle a good wiggle with pliers the rads "smell" hotter.

Would I be right in thinking that in a correctly spec'd and configured CH system, the boiler should really be running pretty much continuosly if the room stat is demanding heat?

[Christian McArdle]

Only with a boiler with a modulating burner. A boiler with a fixed output rate can't possibly be expected to be perfectly matched to the conditions and outside temperature etc. every day of the heating system. Rather than modulating down, such a boiler will cycle. However, provided it isn't too overpowered and the pump is fast enough, the cycling should be reasonably long in period. Not on for a minute and off for a minute.

Christian.