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Posted to uk.d-i-y
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Baxi boiler / New heating/water system problems - help please!!!
wrote in news:fc7746dc-e5ba-4de9-973a-
:
I have had a loft conversion on a two-storey house, now
three storey.
As part of the conversion the hot-water system was changed
from non-
pressurised to pressurised. The new cylinder and associated
pressure
vessels were re-sited in the loft. The top storey radiators
are run
off a separate control system.
Since installation of the new system (last August), I have
had
continual problems with the boiler over-heating and cutting
out,
usually after around 30 minutes but sometimes even more
frequently
than that. The builder has had his heating subbies back
many times
and they have done the following (allegedly):
- replaced the mother board on the boiler
- drained and cleaned the radiator system
- installed an additional pump in series
None of it has made any difference.
The boiler is a Baxi Solo 3 PFL 70. On the ground floor
there are 5
rads, 7 on the first floor and 3 on the second floor.
Finally a different heating engineer came round and
diagnosed the
following:
- boiler too small for the new environment
- flow pipes from boiler to tank should be 28mm, rather than
22mm
(replacing these would involve major work ripping out stud
walls in
the newly finished conversion)
When this information was presented to the builder he
indicated that
this was rubbish and that only a new boiler was required, as
it wasn't
powerful enough. However, surely a weak boiler would just
take longer
to heat up the rads?
On the advice of a friend I de-synchronised the hot water
and central
heating. This cured the problem for about a week; then the
boiler
began cutting out again on the hot water phase, and now is
cutting out
again on the heating phase.
I do not want to have to buy a new boiler if its a simple
problem -
two suggested faults are a new thermostat and a faulty
bypass valve.
Any suggestions as to the likely cause of the problem, or
what to do
next???
Many thanks!
Was the system changed to have all TRV if so was a bypass
circuit fitted.
Does the overheat LED flash or is a constant on
Try turning the boiler thermostat knob to just a quarter on,
i.e. water temp lower then about 63c
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