Radiators not Heating Up

ThisIsWeird

tristanjourney said:

BUFF said:

does your hot water cylinder have an immersion heater &, if so, is that on?

hmm, not sure, how can I find it out?

Are you at the house? Is/has the boiler been on? Is your hot cylinder hot? If yes-no-yes, then where is the magic hot water coming from?

Check your hot cylinder, take photos of it, find the immersion heater (usually a round black cap ~4" diameter sticking out the side of the cylinder with a cable coming out of it), and trace the cable to a switch. Take a photo of that too.

BUFF

tristanjourney said:

BUFF said:

does your hot water cylinder have an immersion heater &, if so, is that on?

hmm, not sure, how can I find it out?

This looks like a clue ...

tristanjourney

I am not at the house atm, but I can find a picture that I previously took. Not sure if this helps.

Thanks @BUFF for referencing the picture in my previous thread. That "only use if gas heating for water not working; electric water heater GAS must be Off" switch is clearly off. Not sure if that is the switch for the immersion heater? Even it is, it's off.

I'll try to reproduce the issue tomorrow morning:
- adjust the valve of the bathroom radiator to the original position (I turned it off the other day); doing this should bring the bathroom radiator hot
- take a picture of the timer for HW and CH
- take a picture of boiler display

ThisIsWeird

Is your cylinder hot? Is the boiler off? If yesx2, then your immersion heater must surely be on. In which case there's a very good chance the bathroom rad is on a gravity circuit from the hot tank - ie, no pump is required; it's just the natural current produced by lighter hot water, and the heavier cooler return.

The immersion heater is that shiny round thingy on the top. Trace that white cable, and see what switch it goes to. If it's 'on', then turn it off...

tristanjourney

ThisIsWeird said:

Is your cylinder hot? Is the boiler off? If yesx2, then your immersion heater must surely be on. In which case there's a very good chance the bathroom rad is on a gravity circuit from the hot tank - ie, no pump is required; it's just the natural current produced by lighter hot water, and the heavier cooler return.

The immersion heater is that shiny round thingy on the top. Trace that white cable, and see what switch it goes to. If it's 'on', then turn it off...

My cylinder isn’t hot. At least I don’t feel it when I touched it. My boiler isn’t off but the timer for HW is off. I checked the switch for the immersion heater, it is off.


I have a theory, but sure if that is possible. I’ll list what I observed first:
• The boiler seems always working, even when CW and HW are off set by timer. Ill attached the display below.
• I vaguely remembered that the radiator symbol will be off when CH timer is off previously, but now it is either illuminated or flashing. All other radiators are not hot though. All other radiators only hot when timer is started.
• I am sure the HW symbol from the boiler display is always on since I first visit this house. Now it is also still always on.
• The internal pump seems always working from the sound I hear and from the display of the boiler.
• I found the bathroom radiator and the pipes near the hot water tank (in the bedroom) have the sounds of something flowing inside when timer is off. The sound is gone when either timer is on.
• There are two pipes near the hot water tank seems always hot, even when timers are off.

My guess is that the internal pump of the boiler is stuck somehow, thus keep heating the bathroom radiator. I am completely a newbie though…

Here is the display of timer and  boiler:

tristanjourney

And this is the switch I can trace back from the immersion heater. It is clearly off now. I am not sure what is the red shining switch though, which is currently on

.

ThisIsWeird

tristanjourney said:

And this is the switch I can trace back from the immersion heater. It is clearly off now. I am not sure what is the red shining switch though, which is currently on

.

The switch with the neon is, I'm guessing, the power supply to your whole CH system. I suspect there's a supply cable going from it to the blue wiring centre to its right.

You can check this - it should be fine to turn it off to see. I'm hoping that everything to do with your system will be shut down - the boiler will go fully off, the programmer ditto, and all sounds of pumps and running water stop.

ThisIsWeird

tristanjourney said:

ThisIsWeird said:

Is your cylinder hot? Is the boiler off? If yesx2, then your immersion heater must surely be on. In which case there's a very good chance the bathroom rad is on a gravity circuit from the hot tank - ie, no pump is required; it's just the natural current produced by lighter hot water, and the heavier cooler return.

The immersion heater is that shiny round thingy on the top. Trace that white cable, and see what switch it goes to. If it's 'on', then turn it off...

My cylinder isn’t hot. At least I don’t feel it when I touched it. My boiler isn’t off but the timer for HW is off. I checked the switch for the immersion heater, it is off.


I have a theory, but sure if that is possible. I’ll list what I observed first:
• The boiler seems always working, even when CW and HW are off set by timer. Ill attached the display below.
• I vaguely remembered that the radiator symbol will be off when CH timer is off previously, but now it is either illuminated or flashing. All other radiators are not hot though. All other radiators only hot when timer is started.
• I am sure the HW symbol from the boiler display is always on since I first visit this house. Now it is also still always on.
• The internal pump seems always working from the sound I hear and from the display of the boiler.
• I found the bathroom radiator and the pipes near the hot water tank (in the bedroom) have the sounds of something flowing inside when timer is off. The sound is gone when either timer is on.
• There are two pipes near the hot water tank seems always hot, even when timers are off.

My guess is that the internal pump of the boiler is stuck somehow, thus keep heating the bathroom radiator. I am completely a newbie though…

Here is the display of timer and  boiler:

Ok, good info. I think we can discount my suspicion of it being a gravity flow from a hot tank - and 'phew' to that.

Pretty clear it's as you say - something is keeping the boiler running when it shouldn't be.

Q - can you ID  for us the pipes which are hot?

Can YOU ID the two motorised valves in that photo? That would be the next thing to suspect for the boiler continuing to run.

Why is the cylinder thermostat removed - see the rectangular hole cut in the insulation with the strap around it? Well, that white thingy lying to its left should be in there. It tells the boiler when the cylinder has been heated enough, so is pretty important. If you post a close up pic of its top, we can guide you on what to check to see if it's working ok. If it is, then it should really be replaced.

Although it's still possible for the towel rail to be on a separate circuit, or on the DHW side, another reason why it's the only rad to be hot is that the others have TRVs turned down low enough.

BUFF

ThisIsWeird said:

tristanjourney said:

ThisIsWeird said:

Is your cylinder hot? Is the boiler off? If yesx2, then your immersion heater must surely be on. In which case there's a very good chance the bathroom rad is on a gravity circuit from the hot tank - ie, no pump is required; it's just the natural current produced by lighter hot water, and the heavier cooler return.

The immersion heater is that shiny round thingy on the top. Trace that white cable, and see what switch it goes to. If it's 'on', then turn it off...

My cylinder isn’t hot. At least I don’t feel it when I touched it. My boiler isn’t off but the timer for HW is off. I checked the switch for the immersion heater, it is off.


I have a theory, but sure if that is possible. I’ll list what I observed first:
• The boiler seems always working, even when CW and HW are off set by timer. Ill attached the display below.
• I vaguely remembered that the radiator symbol will be off when CH timer is off previously, but now it is either illuminated or flashing. All other radiators are not hot though. All other radiators only hot when timer is started.
• I am sure the HW symbol from the boiler display is always on since I first visit this house. Now it is also still always on.
• The internal pump seems always working from the sound I hear and from the display of the boiler.
• I found the bathroom radiator and the pipes near the hot water tank (in the bedroom) have the sounds of something flowing inside when timer is off. The sound is gone when either timer is on.
• There are two pipes near the hot water tank seems always hot, even when timers are off.

My guess is that the internal pump of the boiler is stuck somehow, thus keep heating the bathroom radiator. I am completely a newbie though…

Here is the display of timer and  boiler:

Why is the cylinder thermostat removed - see the rectangular hole cut in the insulation with the strap around it? Well, that white thingy lying to its left should be in there. It tells the boiler when the cylinder has been heated enough, so is pretty important. If you post a close up pic of its top, we can guide you on what to check to see if it's working ok. If it is, then it should really be replaced.

Although it's still possible for the towel rail to be on a separate circuit, or on the DHW side, another reason why it's the only rad to be hot is that the others have TRVs turned down low enough.

if the cylinder 'stat has been removed from the cylinder then fairly obviously it is permanently going to be calling for heat as not reading a hot tank .... At least you have said that you now have the programmer set to off for DHW or the boiler would be running constantly trying to heat a tank that it could not actually measure the temp off.

re. the switched fused spur for the immersion - it is not a type that I am familiar with but to me I would have expected the switch to be more proud when off. Could the switch be broken or not properly off?

plumb1_2

You have Combi boiler installed, it should be a system boiler. So maybe some clown has piped up the rad to the hot water outlet of the boiler.  Never gonna work proper.