Mystery always on towel rails

oniongirl

P.S. if you see any hint of an immersion heater in there let me know  I can see a white cable coming from what I'm presuming is the thermostat for the hot water, but it goes in to the serious business looking grey box that the programmable thingy is seated on that all the other wires to in to 

ComicGeek

You have a branch after the HW valve, which probably means that this is what is feeding your towel rads. When the programmer is off, the boiler is still firing, and the towel rads are hot, check the smaller pipe just below the HW valve. Also check the larger pipe below the HW valve, and see if this is hot all the way to the 'primary coil' on the cylinder (just past the thermostat). Turn down the cylinder thermostat and see if this turns the boiler off.

Something on the HW circuit is maintaining a demand outside of the programmed hours - some controls systems can have a pasteurisation setting which increases the storage temperature temporarily to kill off any germs, and could be faulty. I would definitely get an electrician who understands heating controls to review the wiring.

Also looks like there's a white cabling running down the right hand side of the grey controls box that then goes through the rear wall. Could possibly feed the immersion around the back of the cylinder, but you should have a separate switch for the immersion which isn't visible anywhere.

Personally I don't see the point of having uncontrolled towel rads on the HW primary circuit. I would replumb these onto the heating circuit, but I would have put electric immersions in the towel rads as well for summer use. 

oniongirl

ComicGeek said:

You have a branch after the HW valve, which probably means that this is what is feeding your towel rads. When the programmer is off, the boiler is still firing, and the towel rads are hot, check the smaller pipe just below the HW valve. Also check the larger pipe below the HW valve, and see if this is hot all the way to the 'primary coil' on the cylinder (just past the thermostat). Turn down the cylinder thermostat and see if this turns the boiler off.

Something on the HW circuit is maintaining a demand outside of the programmed hours - some controls systems can have a pasteurisation setting which increases the storage temperature temporarily to kill off any germs, and could be faulty. I would definitely get an electrician who understands heating controls to review the wiring.

Also looks like there's a white cabling running down the right hand side of the grey controls box that then goes through the rear wall. Could possibly feed the immersion around the back of the cylinder, but you should have a separate switch for the immersion which isn't visible anywhere.

Personally I don't see the point of having uncontrolled towel rads on the HW primary circuit. I would replumb these onto the heating circuit, but I would have put electric immersions in the towel rads as well for summer use. 

I'm starting to suspect the HW valve is stuck as there is no resistance when moving it. I've called our plumber fella who fixed the 3-port valve in our last house (when we could only get heating when the hot water was also on), with the hope it's as easy and cheap as that. Presumably if the valve is stuck open, that sends a signal to the boiler to fire.

If the branch is after the valve, I would guess that means that it should only come on when the hot water does? I'm fine with that. It's how our old house worked, although the bathrooms did get a little chilly in the winter. It's tricky... I don't want them on just when heating is on, because then you get damp towels in the summer, but I also don't want my husband to freeze during his 30 minute pooping sessions. Tough call.

coffeehound

ComicGeek said:

Also looks like there's a white cabling running down the right hand side of the grey controls box that then goes through the rear wall. Could possibly feed the immersion around the back of the cylinder, but you should have a separate switch for the immersion which isn't visible anywhere.

 oniongirl said:

P.S. if you see any hint of an immersion heater in there let me know  I can see a white cable coming from what I'm presuming is the thermostat for the hot water, but it goes in to the serious business looking grey box that the programmable thingy is seated on that all the other wires to in to 

Think the round white cap with nothing connected to it is the immersion heater

Jeepers_Creepers

Great photos! Phew - that's some system...

I think Comic has it - the narrower pipes branching off the HW circuit are very likely your towel rad supplies. That's very clever, as you'll be using hot water all through the year, so will have hot TRs too should you want. (Nice warm fluffy towels first thing in the morn, 'cos that's when folk usually set their HW to top-up. Nice)

But, of course, the boiler shouldn't be running when the HW demand is off.

You need someone to be at the HW controller whilst you watch what the 2-port motorised valve does. With the HW demand 'off', the lever should be tight against 'auto' and not easy to move. Turn demand 'on' - the 2-porter should go whhiiirrrrrr for a round 3 seconds and finish with an audible 'click' (as the wee microswitch inside is tripped to turn on the boiler). The lever should be completely floppy along its full travel. Now turn the demand off again - there should be a similar whirrr and a click (the click happening almost first).

Anyhoo, what you have plumbing-wise is great (once it's fixed). You can have warm TRs when you want (as long as the HW is also on). If you don't want them, turn them off at the TRs themselves (one valve should be an obvious control one). Turning them fully off won't affect the boiler's behaviour.

oniongirl

coffeehound said:

ComicGeek said:

Also looks like there's a white cabling running down the right hand side of the grey controls box that then goes through the rear wall. Could possibly feed the immersion around the back of the cylinder, but you should have a separate switch for the immersion which isn't visible anywhere.

 oniongirl said:

P.S. if you see any hint of an immersion heater in there let me know  I can see a white cable coming from what I'm presuming is the thermostat for the hot water, but it goes in to the serious business looking grey box that the programmable thingy is seated on that all the other wires to in to 

Think the round white cap with nothing connected to it is the immersion heater

Yeh.... there's no cable coming from the round white cap thing.

The cable round the side of the grey control box comes from the grey control box and disappears in to nothingness, along with all the other cables, which are then presumably wired to the big HEATING power switch.

Jeepers_Creepers said:

Great photos! Phew - that's some system...

I think Comic has it - the narrower pipes branching off the HW circuit are very likely your towel rad supplies. That's very clever, as you'll be using hot water all through the year, so will have hot TRs too should you want. (Nice warm fluffy towels first thing in the morn, 'cos that's when folk usually set their HW to top-up. Nice)

But, of course, the boiler shouldn't be running when the HW demand is off.

You need someone to be at the HW controller whilst you watch what the 2-port motorised valve does. With the HW demand 'off', the lever should be tight against 'auto' and not easy to move. Turn demand 'on' - the 2-porter should go whhiiirrrrrr for a round 3 seconds and finish with an audible 'click' (as the wee microswitch inside is tripped to turn on the boiler). The lever should be completely floppy along its full travel. Now turn the demand off again - there should be a similar whirrr and a click (the click happening almost first).

Anyhoo, what you have plumbing-wise is great (once it's fixed). You can have warm TRs when you want (as long as the HW is also on). If you don't want them, turn them off at the TRs themselves (one valve should be an obvious control one). Turning them fully off won't affect the boiler's behaviour.

It definitely looks easier to fix that our last boiler set up. It's very neat and tidy. Our last one was clearly a bodge job added on to a million times... but at least it had a working immersion heater for emergencies.

As for monitoring the HW valve - it does nothing, and is totally loose. I've turned the boiler HW temp right down which has at least removed the tap symbol from the info panel showing that HW is being requested (it is still loose when the HW demand is gone by turning the temp down). I will just have to remember to turn it back on again later, otherwise it'll be cold showers all round.

Jeepers_Creepers

oniongirl said:

It definitely looks easier to fix that our last boiler set up. It's very neat and tidy. Our last one was clearly a bodge job added on to a million times... but at least it had a working immersion heater for emergencies.

As for monitoring the HW valve - it does nothing, and is totally loose. I've turned the boiler HW temp right down which has at least removed the tap symbol from the info panel showing that HW is being requested (it is still loose when the HW demand is gone by turning the temp down). I will just have to remember to turn it back on again later, otherwise it'll be cold showers all round.

Yes, it looks like a completely new setup, and very professionally done.

If the motorised valves doesn't shut off, that's pretty much your answer. To be sure to be sure, turn off the boiler isolating switch - to turn off everything. If it doesn't whirrr back with that, then it's definitely stuck open.

If it does now whirr back, then it's not the valve's fault, but something else is telling it to be 'open'. The cylinder 'stat contacts could be short-circuiting, for example. On that point, when you turn the cylinder stat up and down, does it go 'click' at what you believe the water temp to be? (It must do - it turned the boiler off).

If it's the valve, it's an easy fix. The plumber might offer you a choice - replace just the 'head' (no draining of system + a cheaper part) or the whole valve (drain and more costly).

oniongirl

Jeepers_Creepers said:

oniongirl said:

It definitely looks easier to fix that our last boiler set up. It's very neat and tidy. Our last one was clearly a bodge job added on to a million times... but at least it had a working immersion heater for emergencies.

As for monitoring the HW valve - it does nothing, and is totally loose. I've turned the boiler HW temp right down which has at least removed the tap symbol from the info panel showing that HW is being requested (it is still loose when the HW demand is gone by turning the temp down). I will just have to remember to turn it back on again later, otherwise it'll be cold showers all round.

Yes, it looks like a completely new setup, and very professionally done.

If the motorised valves doesn't shut off, that's pretty much your answer. To be sure to be sure, turn off the boiler isolating switch - to turn off everything. If it doesn't whirrr back with that, then it's definitely stuck open.

If it does now whirr back, then it's not the valve's fault, but something else is telling it to be 'open'. The cylinder 'stat contacts could be short-circuiting, for example. On that point, when you turn the cylinder stat up and down, does it go 'click' at what you believe the water temp to be? (It must do - it turned the boiler off).

If it's the valve, it's an easy fix. The plumber might offer you a choice - replace just the 'head' (no draining of system + a cheaper part) or the whole valve (drain and more costly).

I think, though it's hard to be 100% certain, that the only whirr I hear is from the central heating valve. Fingers crossed it's an easy job. Of course our fella is busy on a "proper" job for the next week, so for now I'll just be turning the temperature of the water up and down.

Ganga

Am i missing something but can you not just turn off the towel rail with the two taps at the bottom ( the chrome round things at the bottom of the rad ) turn back on in the winter

oniongirl

Ganga said:

Am i missing something but can you not just turn off the towel rail with the two taps at the bottom ( the chrome round things at the bottom of the rad ) turn back on in the winter

Yes. That stops the rails being hot. But it doesn't stop the boiler firing up and heating the hot water non stop.