Y Plan Boiler Not Turning On

[Bobthebuilder95]

Morning all,

I have recently moved into a new house and have been trying to get the hot water and heating working with no success. Below are my findings so far:

1983 house with Y plan heating system upgrading in 2010 to a Worster boiler.

Boiler when powered on has solid blue light (therefore from my research doesn't have any faults)

The wireless thermostat is successfully turning the relay on and off.

Everything has power (3 way valve, cylinder stat etc) apart from the pump.

Everything is wired back into the old junction box apart from the pump which is wired back into the boiler - which I believe is the norm for new boilers?

So no matter what I set it to I cannot get the boiler to attempt to ignite not power to the pump. Any ideas?

Many thanks, Rob

 

[45yearsagasman]

Do you have power to the switched live on the boiler? The make and model would help.

 

[Bobthebuilder95]

Do you have power to the switched live on the boiler? The make and model would help.

Thanks for the Reply, the boiler is a Worster 18ri. I haven't checked the switched live on the boiler. Can I check this from the junction box?

 

[Harry Bloomfield]

Sounds like a failed / stuck valve actuator, on the 3-port valve.

Set the timer for both HW and CH to be on. Set room stat and cylinder stat to minimum.

Now have someone observe and listen to the 3-port valve, whilst you turn the room stat up. The actuator on top of the valve should be heard to move to the CH position, which should allow the boiler to fire up. It can take several seconds to complete its movement.

Try the above again, but this time turning the cylinder stat up to maximum.

No movement at the valve suggests the actuator has probably failed, or jammed. Try removing the actuator from the valve and manually turning the valve spindle - if that turns fairly easily, then you can probably replace just the actuator. It should be able to turn the D shape on top quite easily, with a pair of pliers/ maybe a bit to tight for bare fingers.

 

[stem]

Have you tried the obvious?

As you have just moved in, is the gas turned on at the meter & boiler?

Is the boiler thermostat turned up?

trying to get the hot water and heating working with no success.

It's unlikely to be the 3-Port motorised valve. Only the central heating uses the motorised valve to start the boiler. When the hot water is required, the cylinder thermostat does it. So even if the valve was faulty, the boiler would still ignite and the pump start when the hot water needs it.

This will probably require a competent person to first of all check and see if there is a live coming into boiler from the external controls. If there is it's a boiler problem. If not it will be a matter of tracing the wiring back to find out the point of failure

 

[Bobthebuilder95]

Have you tried the obvious?

As you have just moved in, is the gas turned on at the meter?
Is the boiler thermostat turned up?


With a 3-Port motorised valve, only the central heating uses the motorised valve to start the boiler. When the hot water is required, the cylinder thermostat does it. Even if the valve was faulty the hot water would still ignite and the pump start.


Failing that, it will require a competent person to first of all check an see if their is a live coming into boiler from the external controls. If there is it's a boiler problem. If not it will be a matter of tracing the wiring back to find out the point of failure

Hi thanks for the reply. Yes there is gas coming in and I believe these worster boilers have a flashing blue light if there isn't gas to them?

And regarding the thermostat yes I have checked this and the relay is clicking on and off with the thermostat being turned up and down.

It's all very strange!

 

[Bobthebuilder95]

That is the wiring inside the junction box if it helps!

 

[stem]

Nothing looks obviously amiss, [apart from the lack of an incoming earth connection with the mains supply, which means the motorised valve & boiler earth connections aren't made ] but the photo doesn't help too much without knowing what the other end of each of the individual wires is actually connected to. Some can be worked out, but for the others there is no standard wiring colour code, so the choices of wire colour would be down to the original installer based on their personal preferences. Also the parallax error makes it difficult to see clearly what wires are in which terminals. For example there are 6 programmer terminals but it only looks like 5 wires, and I can't tell for certain which is vacant. If I had to guess, I would say that the earth terminal is not connected to anything and the earth (green / yellow) wire is being used for something else.......so you see the problem with making assessments from a photo.

Have you checked the fuse in the bottom right hand corner?

If you can access the boiler wiring terminals safely (Note: You should not do this if you have to open a room sealed compartment to access them. With some boilers you do, and some you don't) and have a multimeter and are competent in its use, a check for 230V on terminal strip ST2, and terminal Lr would point you in the right direction. Do the test with the heating and hot water set to be 'on' and room and cylinder thermostats calling for heat. If 230V is present, then the external controls are providing the correct signal, and the boiler is at fault. If there isn't 230V present the fault is with the external controls and / or wiring, which will require further investigation.

If you can't conduct this basic test, or can't access the boiler terminals safely, then you should get someone competent in to fault find. The earthing will need checking too.

 

[Bobthebuilder95]

Nothing looks obviously amiss, [apart from the lack of an incoming earth connection with the mains supply, which means the motorised valve earth connection isn't present ] but the photo doesn't help too much without knowing what the other end of each of the individual wires is actually connected to. Some can be worked out, but for the others there is no standard wiring colour code, so the choices of wire colour would be down to the original installer based on their personal preferences. Also the parallax error makes it difficult to see clearly what wires are in which terminals. For example there are 6 programmer terminals but it only looks like 5 wires, and I can't tell for certain which is vacant. If I had to guess, I would say that the earth terminal is not connected to anything and the earth (green / yellow) wire is being used for something else.......so you see the problem with making assessments from a photo.

Have you checked the fuse in the bottom right hand corner?

If you can access the boiler wiring terminals safely (Note: You should not do this if you have to open a room sealed compartment to access them. With some boilers you do, and some you don't) and have a multimeter and are competent in its use, a check for 230V on terminal strip ST2, and terminal Lr would point you in the right direction. Do the test with the heating and hot water set to be 'on' and room and cylinder thermostats calling for heat. If 230V is present, then the external controls are providing the correct signal, and the boiler is at fault. If there isn't 230V present the fault is with the external controls and / or wiring, which will require further investigation.

If you can't conduct this basic test, or can't access the boiler terminals safely, then you should get someone competent in to fault find. The earthing will need checking too.

Thanks for the reply, see below close up of the programmer wires you are right in that the earth isnt being used as the earth.

Regarding the test can this not be done at the junction box by checking the switched live feed to the boiler is working? Then if it is the issue is on the boiler end and if its not then with the programmer?

Thanks, Rob

 

[stem]

Not ideally, because there could be a fault in the wiring between the wiring centre and the boiler, and it wouldn't test that.

If you wanted to try a test, you could check the various parts of the controls are generating the required signal. Either of the below when the system was operating properly would cause the boiler to run, by generating 230V on the boiler S/L terminal.

1) Check the orange wire in the MID POSITION VALVE terminals with the heating only on and room thermostat calling for heat, should give 230V (hot water to be set off)

2) Check the wire in terminal 1 of the CYL STAT with the hot water only on and cylinder thermostat calling for heat, should give 230V (heating to be set off)

And in both cases is the boiler S/L terminal live also?

 

[Harry Bloomfield]

In your first photo, that looks like a wireless remote control for a wireless room thermostat - the item on the extreme left hand edge of your photo.

If that is a wireless stat, it will not click as you turn the stat up and down, it will just show an LED as lit when there is a call for heat from the stat, at the receiver.

 

[Bobthebuilder95]

Not ideally, because there could be a fault in the wiring between the wiring centre and the boiler, and it wouldn't test that.

If you wanted to try a test, you could check the various parts of the controls are generating the required signal. Either of the below when the system was operating properly would cause the boiler to run, by generating 230V on the boiler S/L terminal.

1) Check the orange wire in the MID POSITION VALVE terminals with the heating only on and room thermostat calling for heat, should give 230V (hot water to be set off)

2) Check the wire in terminal 1 of the CYL STAT with the hot water only on and cylinder thermostat calling for heat, should give 230V (heating to be set off)

And in both cases is the boiler S/L terminal live also?

Thanks, I'll try these and report back

 

[Bobthebuilder95]

In your first photo, that looks like a wireless remote control for a wireless room thermostat - the item on the extreme left hand edge of your photo.

If that is a wireless stat, it will not click as you turn the stat up and down, it will just show an LED as lit when there is a call for heat from the stat, at the receiver.

Yes it is a wireless receiver as I had someone turn the room stat downstairs the light turned on and off and could hear a clicking noise which sounded like a relay.

 

[Harry Bloomfield]

Yes it is a wireless receiver as I had someone turn the room stat downstairs the light turned on and off and could hear a clicking noise which sounded like a relay.

That's OK then..

As you would seem to have the means to check it, you could maybe check if the S/L terminal is becoming live when there should be a call for heat from the boiler - but I don't know if the terminal might be accessible on your boiler.

 

[ianmcd]

can you post a close up of the boiler terminal showing what the terminal not used is please