Can anyone help with this?
After we've run a bowl of water for say washing up, the overheat
thermostat (OT) operates and has to be reset (by pushing down the
button). The strange thing (at least to us) is that this only happens
1. we run the hot water tap for just long enough for the water to get
hot and fill one bowl, and
2. the central heating system is off.
If the central heating is on, the OT doesn't operate and doesn't need
to be reset.
However, if we run the hot water tap for somewhat longer, e.g. to fill
a bath, then the OT does not usually operate (and doesn't need to be
reset), regardless of whether the central heating is on or off.
We've had the system descaled (at substantial cost) but this didn't
solve the problem. The engineer tested the boiler and found that it
was registering a temperature of only about 65 degrees when the OT
operated so there doesn't actually appear to be any overheating. The
OT has in fact been replaced in the past (before descaling was carried
out) but this also didn't solve the problem.
Anyone had the same experience or got any suggestions how to solve the