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I think our boiler is the original from when the house was built in 1972...... Is that a STW record
I realise that is the equivalent of taking off my mudguards.....
I think our boiler is the original from when the house was built in 1972…… Is that a STW record
Getting there, ours is over 30 years old: "Potterton Nettaheat Electonic". The fact it has 'Electronic' in it's name tells you that was cutting edge stuff when they first sold it! It even has 'Electronic' written on it in Space 1999 font!
A quick google suggests 1988 onwards...
If your radiators work then the boiler is fine. It’s probably just the motorised valve which isn’t opening the HW circuit. They have a lever on them you can use to manually over ride. A new valve is about £70, a new motor for a valve is about £20 (if you can find the right one).
Thanks for that. We've just had a plumber in our office to fix our heating and he said the same thing. So I've phoned home with some instructions to open the valve manually. If that fixes if I'll replace the valve.
So I’ve phoned home with some instructions to open the valve manually.
So there are two different set ups.
We have the pipe split after the pump and two motorised valves in parallel, one does CH and one goes to the HW tank, so in our case you pull the lever on the HW tank motor to get HW.
The other set up is all in one with a three way switch (I think) where it can switch on either CH or HW (or maybe both). Never played with one, so not sure how the lever works on those. Someone else on here will know....
Thanks to all the tips I've tracked our problem down to this thing...
When I tried it the other day and when the Mrs checked it today the lever was just flapping around. Tonight when the timer is on and the radiators are roasting but we had no hot water I turned it to manual, felt the resistance and could hear it opening up. Five minutes later, hot tap water. But also full blast heating regardless of where I set the thermostat. So it's all or nothing at the minute.
So not fixed yet but very relieved to know the source of the problem.
When I tried it the other day and when the Mrs checked it today the lever was just flapping around.
OK, when the motor has turned the valve on, the lever goes loose like this. This is normal.
When the motor is off the lever has to overcome a spring to open the valve and normally makes a winding noise as you push it across.
Five minutes later, hot tap water. But also full blast heating regardless of where I set the thermostat. So it’s all or nothing at the minute.
Would need to see a diagram of how your system is plumbed, as in what connects to the output of that valve....
So this is ours (as an example):
The pump pumps downwards and the pipe splits two ways after the pump - water paths shown by red lines. The white box (with black 'X') is the HW motorised valve which controls access to the heating coil in the HW tank. The CH motorised valve (silver box with white 'X') controls access to the CH pipes which dissapear under the floorboards.
With this set up the CH and HW circuits have separate switches. However, when I first bought the house the HW switch was missing and HW was heated whenever the boiler was on. I added it later. Your system might be like this, HW on all the time with the boiler and CH being switched.
[url= https://live.staticflickr.com/65535/51715750896_d9099952ab.jp g" target="_blank">https://live.staticflickr.com/65535/51715750896_d9099952ab.jp g"/> [/img][/url][url= https://flic.kr/p/2mMWJZw ]CH plumbing[/url] by [url= https://www.flickr.com/photos/brf/ ]Ben Freeman[/url], on Flickr
This is what we have. I freely admit I have no idea how it all works...
This is the little lever that wasn't doing anything but I imagine it wasn't 'activated' when I first checked. Last night when we had toasty radiators but no hot water, I pushed it from Auto to Man and heard something kick in.
The gave us hot water but also I think I realised that our radiators are on separate circuits. The ones in the rooms have the adjustable valves on and go on and off with the timer no problem. The radiators in the passage and stairwell don't have the adjustable valve they're just one or off. These are the ones that were blazing last night after I moved that switch. I didn't even know our house could get that hot. I had to switch off the boiler itself to cool it down.
Is this another valve which unleashes something else?
Unfortunately, I've had to come to work again and leave Mrs and baby at home with no hot water and we still can't get a response from any plumbers.
The motorised valve in the bottom picture looks like the one that heats your hot water tank (as it's in that circuit). That's the one you want to manually open to see if that fixes your hot water issue - if it does then it's that valve that's at fault (also check that it's getting power when the hot water is supposed to be being heated).
The valve in your first picture looks like it controls the central heating (but I can't see where the pipe coming out if it is heading). By pushing it to manual you overrode the thermostat so the boiler just kept going and the rads without TRVs kept putting out heat - the ones with TRVs shut down because they'd reached the room temp hat they're set for.
So move that valve back to manual [do this anyway/now] and manually open the lower valve.
I also see what looks like a water thermostat on the cylinder - check what temp thats set for. That could also be a failure point - if it's broken it might stop the valve opening for the hot water.
Oh and I'd be checking the control box with a meter also as a bad connection in there would stop power to a motorised valve or the hot water thermostat.
The main thing is that your boiler is absolutely fine, you just need to find out what's stopping water going from the boiler to the HW tank.
So there's a few things to check but they're not difficult - but move that CH valve back to Auto first.
The trvs will lower the flow rates or shut off the rads where they are fitted. Your hall ones on open loop just fun on f s a. Turn down the stat if they are red hot.
Looking at your photos looks like 1 pump, 2 x solenoid valves plus filling loop, drain valve, 2 or 3 prv for safety.
Dumb q is this gas of just electricity. I can see the tail of the immersion in the piccy but no gas train.
The boiler works if the rads get hot throughout which is great. What you have is a control issue.
Hot water from the boiler goes up stairs to a coil inside a cylinder and back again via the pump.
Hot ch fluid goes round the rads pushed by the same pump.
To allow hot water to be produced without heating the house a valve lets the hot ch fluid go up to the hw tank via a valve and the pump.
In winter another valve opens and lets hot ch fluid circulate round the rads in a out and back loop. This is controlled by the lower lhs valve i think.
It will be the highest rhs valve that lets ch fluid recirc through the hw cylinder, indirect heating system. Hopefully its just this thats stuck shut or broken. Iirc the tops come off and you can manually operate them, or slide lever operates the valve.
These are not expensive and ypu can switch the motorised valve yourself
It will be the highest rhs valve that lets ch fluid recirc through the hw cylinder, indirect heating system.
Why?
If you look in the picture it's the lower motorised valve that's in the HW heating circuit and the upper one doesn't seem to be related to the HW circuit as all.
Could be wrong obvs.
I think you correct. A closer look reveals the ch drain down point under the solenoid, however that could also enable drainage of the indirect loop.
From that pic its impossible to tell
We pretty much typed the same thing
Easy way to tell. Hold pipe up stream of valve. The one that doesn't burn your hand is busted
From that pic its impossible to tell
It looks like the pipe coming out of the [bottom of] the lower motorised valve goes straight into the tank - in which case that valve is controlling the HW.
The one that doesn’t burn your hand is busted
As I said, the valve might be fine, the issue might be power getting to it or the HW thermostat saying that the water hot when it's not (i.e. it's bust!).
The first thing to discover is whether the valve will open manually and if this fixes the issue. If it does then why isn't it opening automatically? - either the valve is bust or there's an 'electrical' issue (which could just be a connection)
So move that valve back to manual [do this anyway/now] and manually open the lower valve.
A quick check of my post and this is wrong as it should read "move that valve back to Auto..."
(I did word it correctly further down the post though!)
I had that setup at my old house.
The micro switches that signal to the boiler and pump to start when the valve is open are notoriously unreliable on Danfoss valves.
It’s a 15 minute job to change the valve head but because the valves and cylinder are supplied to the house builder as a complete kit you’ll have to connect it to the wiring centre yourself (note the coloured connectors which are fitted at the factory).
Open wiring centre, take photo of existing layout and then connect in the new valve head. It’s all colour coded.
This is what we have. I freely admit I have no idea how it all works…
Looking at the plumbing I'm not surprised, seems to unnecessarily complicated...
Thermal store.
🙂
Read through some of this and having had a recent thread on boiler woes, I'll throw my tuppence in ...
Our boiler stopped working, coinciding just after a boiler service. That service engineer didn't chose to come back. Phoned another boiler chap, he wasn't sure but thought maybe silt in the pipes stopping water flow, but went away having 'cleared' part of a pipe and the boiler still didn't work (he blamed the lack of gravity not being able to pull water down). Third plumber convinced the boiler was on its last legs so start with the pcb, and then work through each part of the boiler replacing it.
Through lots of good help on here, it boiled(!) down to a:
1. motorised HW valve stuck open - simple fix
2. some silt in the pipe just before the circulating pump - cut it out and replaced (and replaced pump at the same time as it's v old)
3. condensor trap blocked
4. condensor piping (which has severla 90degree bends) blocked
Now it's purring away.
And none of the plumbers suggested these things. And our boiler is v old, so there's hope!
I managed to get a reply from an actual plumber today. He asked what the problem was, I sent him the pictures and he said he'd get back to me with a price and a date. This was at 1pm and I've heard nothing since.
The Danfoss thing is back on auto. I can't see how to switch the bottom one to manual. It's not obvious and I haven't crawled into the cupboard for a look. I might have a look when mini me is finished screaming himself to sleep. My head is pretty battered by this time on an evening now.
He asked what the problem was, I sent him the pictures and he said he’d get back to me with a price and a date. This was at 1pm and I’ve heard nothing since.
I imagine the run up to Xmas with the temp dropping and everyone switching CH on means plumbers are pretty busy. Plus stuff like this are low value jobs with all the same faff of visiting, quoting, getting parts etc.
I can’t see how to switch the bottom one to manual.
Probably doesn't have a "manual" setting I've never seen that before but I'm not a plumber).... Just move the black lever over to the other side - this is what would happen when the motor does it.
The gave us hot water but also I think I realised that our radiators are on separate circuits. The ones in the rooms have the adjustable valves on and go on and off with the timer no problem. The radiators in the passage and stairwell don’t have the adjustable valve they’re just one or off.
Could just mean no one bothered to put TRVs on them. I didn't bother in the bathroom, for example, as we'd always want that one on to dry towels etc.
Probably less likely that you have radiators on different circuits, but not impossible.
These are the ones that were blazing last night after I moved that switch. I didn’t even know our house could get that hot. I had to switch off the boiler itself to cool it down.
Well the mechanical over ride switch over rides everything inc thermostats etc, so the boiler just keeps going and only its internal water temp sensor (probably set about 70C) is holding it back. So it will keep heating the HW / radiators for ever - which, unless it's sub zero outside, will get the house pretty toasty.
NB The boiler will have been designed to run like this, so I doubt it has really 'over heated', it's just you've not seen it that warm before. Older boilers don't have much insulation, so act as a mini-radiator.
Whilst you're using the manual over ride, you could turn the boiler temperature down a bit, normally a dial on the boiler control panel. Sometimes its marked in degrees C, ours is just - / +, so just trial and error.
I contacted SIX plumbers today. The sixth one has just left. He said he could come right away or I can wait two weeks.
Two new motorised valve things (which look a lot more robust than the old plastic ones) fitted for £165. It now appears to be working perfectly and I feel massively relieved.
As soon as he looked in the cupboard he spotted that the expansion tank was full of water. No idea how he did that. He said we need a new one as it's just pouring the excess water down the drain but that's a job for another day.
He also said we've got one of the most unreliable boilers ever made. But, it fired up and it's working fine for now.
Also, Doris and Mini-me are visiting family over a hundred miles away so I'm looking forward to a night of uninterrupted sleep and a couple of days without changing any nappies.
Two new motorised valve things (which look a lot more robust than the old plastic ones) fitted for £165. It now appears to be working perfectly and I feel massively relieved.
Pretty good value!
A bit of parts darts there!
The chances of both motorised valves being borked at the same time is very, very slim - and we know the CH one was fine as the radiators were working.
But hey..... You've got it sorted and hopefully learnt a bit about CH systems.
Yeah you're right but I honestly don't mind paying to have two new ones. I was expecting the bill to be in the multiple hundreds so it's not too bad.
I can sort of see why he changed both as whilst you drain the system etc, you may as well change both as that will buy another 5 ish years of working motors etc. Otherwise he could be back in 3 months to drain the system and swap out the other one.....
I can sort of see why he changed both
Yeah I’d do both whilst it was drained down. Not worth the time diagnosing which one. And if one’s gone end of life, other won’t be far off. Sensible approach.
Want to hear something funny?
Boiler is dead. It's gone completely silent and turning it off and again doesn't fire it up. No heating, no water, nowt.
This plumber did make a right song and dance about how crap my particular boiler is and how unreliable they are and sometimes when you switch them off they just don't come back on. But it's worked fine all this time. Then when he left he texted me a quote for a replacement.
Is it possible he put a hex on it? I did have to leave him alone while I went to a cash point. He could have done a magic dance or just stabbed it with a screwdriver or anything.
What a shitty week.
The boiler is either an Ideal Icos or Potterton Suprima I think is the model. Both truly awful but the icos wins it for me
Oh FFS!
Maybe there's air in the system that's caused the boiler to lock out?
Did he/have you bled the rads?
Did he actually drain right down to swap the motorised valves or just close the valves above them?
Is there power going to the boiler?
The boiler is either an Ideal Icos or Potterton Suprima I think is the model. Both truly awful but the icos wins it for me
We have an Ideal Icos.
I've just had him on the phone we're trying to troubleshoot it. It's past my bedtime.
Did he actually drain right down to swap the motorised valves or just close the valves above them?
He just said he didn't drain the system, just the pipes in front of the tank.