Hello,
For the last 2 or 3 months the RCD in our consumer unit has started to
trip intermittently. All the sockets and boiler are on this circuit.
The RCD only ever trips when it is wet and windy and always happens in
the evening. After much unplugging and testing sockets I've finally
traced the problem to the boiler. The last time the RCD tripped and I
reset it I noticed that it stayed on for a few seconds, then when the
boiler fired up it trips. So here's what I have done so far:

RCD tripped (Wet and windy weather outside)
Turned boiler off and room thermostat to zero
Reset RCD - it stayed up
Turned on boiler - RCD still OK
Turned room thermostat up to fire up boiler - RCD tripped straight
away

To discount the pump I unwired it - the RCD still tripped when
turning the thermostat to fire up the boiler.

So I was thinking that this could be the room thermostat but then
thought it's more likely to be the boiler. With just the hot water on
the RCD didn't trip but this could be due to the hot water cylinder
being full so the boiler wasn't heating any water.

What's puzzling me is why this only happens in wet and windy weather
and only when the boiler fires up. The boiler is in the garage and has
a vent pipe that goes out the side of the garage wall. What would be
the next best cause of action? Get an electrician or plumber in or is
there something else that I can do to further diagnose?

Thanks

Pete

Pete wrote:

Hello,
For the last 2 or 3 months the RCD in our consumer unit has started to
trip intermittently. All the sockets and boiler are on this circuit.
The RCD only ever trips when it is wet and windy and always happens in
the evening. After much unplugging and testing sockets I've finally
traced the problem to the boiler. The last time the RCD tripped and I
reset it I noticed that it stayed on for a few seconds, then when the
boiler fired up it trips. So here's what I have done so far:

RCD tripped (Wet and windy weather outside)
Turned boiler off and room thermostat to zero
Reset RCD - it stayed up
Turned on boiler - RCD still OK
Turned room thermostat up to fire up boiler - RCD tripped straight
away

To discount the pump I unwired it - the RCD still tripped when
turning the thermostat to fire up the boiler.

So I was thinking that this could be the room thermostat but then
thought it's more likely to be the boiler. With just the hot water on
the RCD didn't trip but this could be due to the hot water cylinder
being full so the boiler wasn't heating any water.

What's puzzling me is why this only happens in wet and windy weather
and only when the boiler fires up. The boiler is in the garage and has
a vent pipe that goes out the side of the garage wall. What would be
the next best cause of action? Get an electrician or plumber in or is
there something else that I can do to further diagnose?

Thanks

Pete

you already know how to divice and conquer, just carry on, divide more
until youre only left with one thing that must be at fault. Then it
will likely be easy enough to see why its tripping.


NT

In an earlier contribution to this discussion,
Pete wrote:

Hello,
For the last 2 or 3 months the RCD in our consumer unit has started to
trip intermittently. All the sockets and boiler are on this circuit.
The RCD only ever trips when it is wet and windy and always happens in
the evening. After much unplugging and testing sockets I've finally
traced the problem to the boiler. The last time the RCD tripped and I
reset it I noticed that it stayed on for a few seconds, then when the
boiler fired up it trips. So here's what I have done so far:

RCD tripped (Wet and windy weather outside)
Turned boiler off and room thermostat to zero
Reset RCD - it stayed up
Turned on boiler - RCD still OK
Turned room thermostat up to fire up boiler - RCD tripped straight
away

To discount the pump I unwired it - the RCD still tripped when
turning the thermostat to fire up the boiler.

So I was thinking that this could be the room thermostat but then
thought it's more likely to be the boiler. With just the hot water on
the RCD didn't trip but this could be due to the hot water cylinder
being full so the boiler wasn't heating any water.

What's puzzling me is why this only happens in wet and windy weather
and only when the boiler fires up. The boiler is in the garage and has
a vent pipe that goes out the side of the garage wall. What would be
the next best cause of action? Get an electrician or plumber in or is
there something else that I can do to further diagnose?

Thanks

Pete

What actually switches the boiler on? Have you got any motorised valves? If
so - certainly in CH-only mode - it will be a valve actuator which switches
the boiler on after the programmer/room stat have told the valve to motor to
the CH position.

So it could be a valve - rather than the boiler itself - which is causing
the RCD to trip. I've no idea why this only happens in wet and windy
conditions - unless the valve is located somewhere where rain water could be
blown into its electrics.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

Hello,
Thanks for the replys - the RCD tripped again today (wet and windy
weather again).
With the central heating off, the RCD trips when the hot water comes on
as well.
The winds died down and the rains stopped and I can get CH and HW both
on without tripping the RCD.

I had a look at the vent that comes out of the top of the boiler and
I'm wondering if this could be the problem - the boiler vents out of
the top, theres then a 90 degree bend and the the vent pipe goes
through the garage wall and outside - this horizontal vent pipe to the
outside is actually at an angle - it slopes down to the boiler - I
would have tought that it should slope away from the boiler - could it
be that the wind is blowing rainwater into the vent and then this is
running into the boiler?

I'm unable to see any other valves that could get wet.

Thanks

Pete


Roger Mills wrote:
In an earlier contribution to this discussion,
Pete wrote:

Hello,
For the last 2 or 3 months the RCD in our consumer unit has started to
trip intermittently. All the sockets and boiler are on this circuit.
The RCD only ever trips when it is wet and windy and always happens in
the evening. After much unplugging and testing sockets I've finally
traced the problem to the boiler. The last time the RCD tripped and I
reset it I noticed that it stayed on for a few seconds, then when the
boiler fired up it trips. So here's what I have done so far:

RCD tripped (Wet and windy weather outside)
Turned boiler off and room thermostat to zero
Reset RCD - it stayed up
Turned on boiler - RCD still OK
Turned room thermostat up to fire up boiler - RCD tripped straight
away

To discount the pump I unwired it - the RCD still tripped when
turning the thermostat to fire up the boiler.

So I was thinking that this could be the room thermostat but then
thought it's more likely to be the boiler. With just the hot water on
the RCD didn't trip but this could be due to the hot water cylinder
being full so the boiler wasn't heating any water.

What's puzzling me is why this only happens in wet and windy weather
and only when the boiler fires up. The boiler is in the garage and has
a vent pipe that goes out the side of the garage wall. What would be
the next best cause of action? Get an electrician or plumber in or is
there something else that I can do to further diagnose?

Thanks

Pete

What actually switches the boiler on? Have you got any motorised valves? If
so - certainly in CH-only mode - it will be a valve actuator which switches
the boiler on after the programmer/room stat have told the valve to motor to
the CH position.

So it could be a valve - rather than the boiler itself - which is causing
the RCD to trip. I've no idea why this only happens in wet and windy
conditions - unless the valve is located somewhere where rain water could be
blown into its electrics.
--
Cheers,
Roger
______
Email address maintained for newsgroup use only, and not regularly
monitored.. Messages sent to it may not be read for several weeks.
PLEASE REPLY TO NEWSGROUP!

In message . com, Pete
writes
Hello,
For the last 2 or 3 months the RCD in our consumer unit has started to
trip intermittently.


What boiler ?

--
geoff

Pete wrote:

I had a look at the vent that comes out of the top of the boiler and
I'm wondering if this could be the problem - the boiler vents out of
the top, theres then a 90 degree bend and the the vent pipe goes
through the garage wall and outside - this horizontal vent pipe to the
outside is actually at an angle - it slopes down to the boiler - I
would have tought that it should slope away from the boiler - could it
be that the wind is blowing rainwater into the vent and then this is
running into the boiler?

Is it a condensing boiler? If so then then flue should slope back toward
the boiler, and it will be designed to accept water running into the
flue. If however it is a conventional boiler then the flue should slope
away from it a little.

Perhaps positioning a baffle a little in front of the flue to block the
wind/rain would help diagnose if tis is the problem?


--
Cheers,

John.

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