Even when you have turned your heating and hot water to the off position?Right. So measured between the blue (N) and grey wire (4) on the PCB - and it's always 244V
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Even when you have turned your heating and hot water to the off position?Right. So measured between the blue (N) and grey wire (4) on the PCB - and it's always 244V
Yes - heating and hot water being off (on the Nest)!Even when you have turned your heating and hot water to the off position?
I would now test between neutral and brown of both of your zone valves when heating and hot water is still in the off position. Hopefully you won’t have 230 volts there. I would then separate the oranges on your zone valves and measure between neutral and each of the oranges in turn to see if one of your zone valves has an issue. Could be a micro switch issue In one or both of your zone valves.Yes - heating and hot water being off (on the Nest)!
I have 244VI would now test between neutral and brown of both of your zone valves when heating and hot water is still in the off position. Hopefully you won’t have 230 volts there.
They both have 244vI would then separate the oranges on your zone valves and measure between neutral and each of the oranges in turn to see if one of your zone valves has an issue.
If you have 244v between neutral and the terminal where your brown of the zone valves are connected in your wiring centre, when the heating and hot water are in the off position, then you have a problem possibly from the nest end.I have 244V
They both have 244v
any ideas?
I see...If you have 244v between neutral and the terminal where your brown of the zone valves are connected in your wiring centre, when the heating and hot water are in the off position, then you have a problem possibly from the nest end.
You shouldn’t see 230v between neutral and brown when your heating and hot water are in the off position.I see...
So it could be the Nest's fault after all? (I spoke to Google who wants a "diagnostic" in order to send a replacement..)
Assuming you have seen the photo of the cabling at Nest? That seems correct?
Many thanks for your help!
OK, so I checked again (my heart sunk before)
and
b/w Neutral and Brown on both ZV = 0v
b/w Neutral and Orange on both ZV = 244v
All while heating & HW OFF
Apologies, about the wrong info earlier...230v should only be present between neutral and orange when you select either heating or hot water after the valve has motored open
one like this?
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Thanks for the instructions!I would remove the permanent live from the valves by disconnecting the orange from the top of 11 and move it to the spare of 5. The spare black looks like it goes to the boiler. I'd connect that to 5 in the junction box and connect the black to 3 in the boiler.
HmmIf you look at the side of the valves there's a manual override. When it's energised you will see it move. You can force it on by pushing it to the open position and holding it up while it tries to close on the spring.
If they are both operating as expected mechanically and you are getting voltage on the orange with the valve in the closed position you have a faulty auxiliary switch which might have been what the electrician was referring to.
Yeah that's what I was proposing. You would be removing the switch from the permanent live in the junction box and using the one in the boiler instead.Just to make sure I don't misunderstand please see photos below - can you please confirm?
Thank you for clarifying, Brian!!In its rest position, a zone valve does not allow water to flow through it.
Applying 230V across the blue and brown wires opens the valve, so that water can flow, and also closes a switch between the orange and grey wires.
There is no electrical connection between the brown/blue wires and the orange/grey wires.
The power to the brown and blue wires should be controlled by the heating control system - thermostats, programmer, Nest, etc.
The boiler and pump should be controlled solely by the orange and grey wires, with no direct connection to the afore mentioned control system.
The boiler may also have a permanent live feed, which it uses to power the pump for a short while after the boiler has shut down, to prevent local overheating in the boiler.
thanks for the heads upBefore you go any further with this make sure you have the legionella prevention switched off in Nest settings as having this activated even with HW an CH in off boiler can kick in
Before you go any further with this make sure you have the legionella prevention switched off in Nest settings as having this activated even with HW an CH in off boiler can kick in
As I understand it, he's tried this approach five times. It's the 'competent' bit that appears to be the stumbling block.I would advise you find a competent person to resolve this issue
OK, so
I followed Aaron's instructions - and the boiler still fires up immediately - with HW&heat OFF.
Then I check voltage to ZV's again
with HW&heat OFF > 244V
with HW&heat ON > 0V
Is it me, or should it be the other way around??
Hi @westward10@dfreitag this thread is drifting into a step by step guide which the forum generally does not permit and I admit I have let it run as those contributing are knowledgeable people however, the meter you are using is not appropriate for verifying mains voltages which the forum cannot condone. I understand you have spent a considerable amount of money with no resolution but this thread has been running for nearly a week and I would advise you find a competent person to resolve this issue and whilst they are at it install those flexible cables in a professional manner.
That's really great! Good to know we reached thisYour wiring should now resemble the s-plan diagram in the nest instructions minus the boiler being called for and not power cycled.
B/w orange & brown core I still getThe voltage should only be present on the orange core when the valve is open, the small valves only have a normally open contact the bigger valves also have a white core. Something is amiss there.
Do I understand correctly - are you saying this was NOT a new PCB? (the guy who installed it claimed it was and charged accordingly..)The boiler should only run when there is a connection between 3 and 4. If there's nothing connected in-between the boiler shouldn't run. That PCB looked suspect with all of the flux, I couldn't tell if the joints were dry or take a guess at the function of the repaired section from the photo however.
Thanks for all your help @Aaron b - much much appreciated!!Hopefully you have enough information to get someone to complete the troubleshooting. Good luck with it.
Just to chip in to Aaron b's observations:Do I understand correctly - are you saying this was NOT a new PCB? (the guy who installed it claimed it was and charged accordingly..)
Is that radiator in a bathroom? It's normal for the radiatot/towel rail in a bathroom to be connected so that it gets hot when either heating or hot water is on. The theory behind this is to allow wet towels to be dried all year round.Also, just noticed another symptom. One of my radiators (the one right above the boiler) is heating up when I get the hot water to heat..
B/w orange & brown core I still get
when HW&heat OFF > 244V
when HW&heat ON > 0V
This is a common way of connecting bathroom radiators, but the same effect can occur if a common plumbing mistake is made. If a boiler has a single hot water return port, the return from the HW cylinder must tee into the return trunk nearer to the boiler than any radiator. If not, a venturi effect will occur with the cylinder return water flowing past the radiator tee, sucking water from the radiator branch, through the radiator, along the heating feed trunk from another radiator, and from the return trunk where that radiator tees in. This water will be drawn the wrong way along the return trunk, from the cylinder return, so will be hot, and will heat the radiators.Is that radiator in a bathroom? It's normal for the radiatot/towel rail in a bathroom to be connected so that it gets hot when either heating or hot water is on. The theory behind this is to allow wet towels to be dried all year round.
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