is there something wrong with my heating system?

[diy888seeker]

Hi guys,
Sorry if my question sounds stupid, but this is the first time that I have used a conventional boiler (always been combi). We moved into this house a month ago and it feels like the heating is not enough.

Whenever I increase the temperature and hear the click on the mechanical thermostat (new), the boiler doesn't kick in (with the timer disabled). Should it always fire up when you increase the temperature to the point where the thermostat clicks and lights up? Mind you it turns itself on and off like it has a another thermostat hidden somewhere. There are no TRVs in the house.

Is this really how a conventional heating works? Or is there something wrong with my boiler (old boiler) ?

Thanks

 

[leakydave]

The time clock should also be set to HEATING ON for the heating to work

 

[diy888seeker]

The time clock should also be set to HEATING ON for the heating to work

Sorry I forgot to mention, the time clock is in the the ON position

Going back to my original question, is my boiler functioning as it should?

 

[JohnD]

When you turn up the room stat, the pump should start spinning. Does it?

You probably have a 3 port valve near the pump. Does it whirr briefly?

Post some pics.

 

[diy888seeker]

When you said whirr briefly, is that like 5-seconds? They are far away, I will get back to you on that as I am alone in the house. Meanwhile this is the setup (pics). Its whirring for hours now. I will upload later

What's with the tape on the switch? What is the switch for?
View media item 58946 View media item 58947 View media item 58948

 

[JohnD]

the switch appears to be for the immersion heater.

 

[diy888seeker]

Yes but why does it have a tape on it?

By the way,going back to my original question:

When the boiler is on the ON position, and the room is really cold, why is it that when I increase the temperature on the thermostat to the point of "click" the boiler doesnt fireup straight away? I know it should fireup on a combi boiler but on a conventional system, I am not sure.

 

[JohnD]

to get some clues as to why:

When you turn up the room stat, the pump should start spinning. Does it?

You probably have a 3 port valve near the pump. Does it whirr briefly?

 

[diy888seeker]

Hi everyone,
I did the test minutes ago, the pump does not whirr when I bump up the temperature on the thermostat. Is that bad?

 

[JohnD]

does the motorised valve (rectangular metal box at the "T" pipe junction) whir briefly when the hw or the ch are switched on and off, at the timer and/or the thermostat? It contains a switch that operates after it has moved.

undo the silver screw in the middle of the pump front (water will not gush out). Can you turn the spindle inside with a flat screwdriver, or is it jammed?

does the pump ever vibrate? even if you turn the speed to "3"?

 

[MANDATE]

From you photos you have a 'Y' plan system. It is all centered around the 3 port mid position valve.
Whenever the boiler is running so is the pump.
It's down to the position of the 3 port valve that decides where the water from the boiler goes.
You have the option to select HW only or CH only. There is a third option to have both HW and CH selected.With this option the valve opens and moves to mid position only so HW and CH both get a share of the water, but this is only until one side becomes satisfied and then the valve moves so the not yet satisfied side gets all the water.
The HW is controlled by the cylinder stat and the CH is controlled by the room stat
The 3 port valve is most likely related to your problem. It's spring loaded return valve. Returns to HW position unless motor still energised. HW not usually a problem.
Providing the motor in the valve is OK and micro switch no 1, going to mid position is not normally a problem.
Now going from mid position to CH position and then lighting the boiler does rely on a few things.
Faulty micro switch contacts can stop valve from moving forward, or even if it does move correctly the second micro switch if faulty does not allow power out from valve to light boiler.
There is another issue regarding the valves movement over the second section. The power from the room stat gets the valve half way, this power is then lost and replaced with power from a different source (well two sources to be exact)
If you follow the wiring diagram for a 'Y' plan you'll see a wire from the programmers HW OFF terminal going to the valves grey wire and als o one from the cylinder stat.
For some reason some sytems have not had the wire from HW OFF and the system does not function as it should.
In a nutshell you need to know just how this system works to be able to check which bit is not doing what it should.
I've had two problems: 1. the motor was faulty. 2 valve moved OK but faulty micro switch did not allow boiler or pump.
Just take note of this: power to run boiler/pump comes from cylinder stat when HW is involved in the requirement. When CH is the only involvement power to run boiler/pump comes through valves orange wire.
The wire from valve and wire from cylinder stat of course connect to each other

 

[diy888seeker]

does the motorised valve (rectangular metal box at the "T" pipe junction) whir briefly when the hw or the ch are switched on and off, at the timer and/or the thermostat? It contains a switch that operates after it has moved.

undo the silver screw in the middle of the pump front (water will not gush out). Can you turn the spindle inside with a flat screwdriver, or is it jammed?

does the pump ever vibrate? even if you turn the speed to "3"?

Hi JohnD,
It doesn't whir or anything, but once in a while the pump turns on (with a gushing sound) for a few minutes and off for a very long time before it fires up again, its really cold before the pump decides it needs to turn on again. The speed is already in 3, it was like that when we moved in. Where should it be normally?

CH is not totally dead, it works once in a while, I can hear the sound of gushing water when pump is on and radiator is hot, but main problem is when its cold and i turn up the thermostat to the highest setting, pump it doesn't turn on. It just feels like my room thermostat is not working.
I have not checked the spindle in the pump as I think it works, do I still need to check?

I don't know if its relevant but if I increase the cylinder thermostat from 60 to say 63, pump turns on.

 

[diy888seeker]

From you photos you have a 'Y' plan system. It is all centered around the 3 port mid position valve.
Whenever the boiler is running so is the pump.
It's down to the position of the 3 port valve that decides where the water from the boiler goes.
You have the option to select HW only or CH only. There is a third option to have both HW and CH selected.With this option the valve opens and moves to mid position only so HW and CH both get a share of the water, but this is only until one side becomes satisfied and then the valve moves so the not yet satisfied side gets all the water.
The HW is controlled by the cylinder stat and the CH is controlled by the room stat
The 3 port valve is most likely related to your problem. It's spring loaded return valve. Returns to HW position unless motor still energised. HW not usually a problem.
Providing the motor in the valve is OK and micro switch no 1, going to mid position is not normally a problem.
Now going from mid position to CH position and then lighting the boiler does rely on a few things.
Faulty micro switch contacts can stop valve from moving forward, or even if it does move correctly the second micro switch if faulty does not allow power out from valve to light boiler.
There is another issue regarding the valves movement over the second section. The power from the room stat gets the valve half way, this power is then lost and replaced with power from a different source (well two sources to be exact)
If you follow the wiring diagram for a 'Y' plan you'll see a wire from the programmers HW OFF terminal going to the valves grey wire and als o one from the cylinder stat.
For some reason some sytems have not had the wire from HW OFF and the system does not function as it should.
In a nutshell you need to know just how this system works to be able to check which bit is not doing what it should.
I've had two problems: 1. the motor was faulty. 2 valve moved OK but faulty micro switch did not allow boiler or pump.
Just take note of this: power to run boiler/pump comes from cylinder stat when HW is involved in the requirement. When CH is the only involvement power to run boiler/pump comes through valves orange wire.
The wire from valve and wire from cylinder stat of course connect to each other

Hi Mandate
The pump works once in a while so does that mean the micro switch is faulty? Pump does sounds working a few times in a day (with gushing sound) is that okay? I dont even know if gushing sound from the pump is normal.