I have a boiler which will switch on with the timer in the morning and
the evening if I have the Hot water only set. However if I set the
time to be longer than an hour it will not come on. Even if I leave it
for a couple of hours and try and switch it on it still won't come on.
However if I swithc on the CH then the boiler does switch on - but
only for the CH (even if the HW is on). The boiler services a hot
water cylinder which is on the first floor and the water is pumped to
this cylinder from the boiler.
Wierd! Can you give a bit more information about your system.
Make and model of timer?
What thermostats are there, and what temperatures are they set to?
What zone valves or 3-port valve do you have?
Is this a new problem, or hasn't it ever worked properly?
Boiler won't fire up unless the cylinder really needs heating.
I doubt it takes an hour to heat it up, so it will be up to
temperature at that point.
My hot water cylinder is only heated for 30 minutes in the morning.
I agree entirely. However, my interpretation of the original post - rightly
or wrongly - was that, if the timer was set for more than an hour, the water
didn't heat *at all* - rather than heating for an hour and then stopping.
The boiler does fire in the morning, but it won't fire for much longer
than an hour. Its enough for 2 showers and then there's no HW until
the next day!
This was not a problem in the past it only started happening in the
last few months. I used to have the HW set for a much longer period in
the past and the boiler would come on when either the water cooled
down or was used up. I have a programmer (manufactured by LAdnis and
Gyr) and the system I believe is a fully pumped one.
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