"Nigel Percy" wrote in message
om...
All CH Experts...

Background

Conventional Ideal FF380 80,000btu Boiler
13 Rads (No TRV's) and Programmable Thermostat
System just balanced - temp drop of 11/12 degree C
across all rads and boiler. Pump speed on minimum.

Problem:-
The boiler will fire continously while the house is
warming up from cold in the morning but for a short
period just before the room stat is satisfied the
boiler will short cycle, Fire for 2 mins off for about
the same duration. This will happen until the room
stat switches the boiler off.

It only tends to happen in the morning when warming
the system up from cold.

This may be the boiler stat faulty or a slow running pump. I assume the
house is still cold and the thermostat is calling for heat.

- The heat appears not to be getting out of the boiler fast enough
- the boiler stat is faulty,
- the boiler is way too large.

When demand is triggered
during the day/evening to top up the temp it seems
to fire continuously until the room stat is satisfied.

So all is right when the room stat is in control. It may have a boiler
anti-cycle function so all is fine when it is mainly in charge.

Obviously this is the boiler stat turning the boiler
off but I wouldn't of thought this would happen as the
flow temp from the boiler is 74 degree C and the return
about 62 degree C.

Is the problem the amount of time it takes to heat the
house up in the morning?

Is it a problem or am I concerning myself about something
that isn't a problem

If it's a problem is there a solution?

Needs a little more observation and seeing if the boiler is too big.
Cheers

Nige


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