Friend with no hot water. Help.

[dobbslc]

I need a bit of advice on 2 port motorised valves!
I have a friend that has had no hot water for 2 days and his missus is going to kill him soon if it doesn't get fixed!
It's been playing up for months so he's been using the immersion heater to get hot water even though the boiler and heating are working fine £££££.
Now the immersion heater has also stopped working hence no hot water!
I had a look last night and found the immersion safety trip had popped out so reset that and it's now working fine. I've turned that off for now.
The picture below shows what he's got installed. Two cylinders paired together.

There's hot water to the top of both the valves. The valve on cylinder 1 doesn't seem to work but when I move the override lever it flows and the cylinder heats up, the valve on cylinder 2 also doesn't seem to work and has the lever missing.
I've left the valve on cylinder 1 in the override position so they are getting some hot water for now.
Questions are:
1 Could it be that both valves have failed or whatever sends them a signal has failed .
2 is it safe to leave the valve on cylinder 1 overridden until he gets a plumber out?
Thanks

 

[brightspark]

if u have overridden the valve and the boilers come on its the motorised valve motor faulty some are replaceable and only cost 12 quid from screwfix the type with the pressed steel cover ones if not get a replacement head for the valve check the cylinder thermostats to make sure its getting power. what make are the valves and mod number

 

[thinfourth]

The motorised heads should clip off and be a simple follow the colours to change the wire

But a plumber will be along later to either suck his teeth and go £500 of some useful advice

 

[dobbslc]

@brightspark the boiler was already on as the heating was on, I didn't think to check it by turning the heating off!
There was an old motor laying under the valve on cylinder 1 so I think the last plumber had changed it.

 

[Kayos]

The motorised heads should clip off and be a simple follow the colours to change the wire

But a plumber will be along later to either suck his teeth and go £500 of some useful advice

£350 plus vat for 1, needs a full drain down, fill up, new chemicals plus messing about firing it up. If it goes well its half a day if it doesn't it could well be a full day. With 2 cylinders its unlikely to be a 1 bedroom flat

Get it wrong and it will cost much much more than £500

 

[brightspark]

complete screw on heads can be had for about

@brightspark the boiler was already on as the heating was on, I didn't think to check it by turning the heating off!
There was an old motor laying under the valve on cylinder 1 so I think the last plumber had changed it.

was it a little round one with a cog and 2 orange leads they are pretty crap sometimes and don't last long there only held inb with one screw and u turn it slightly to remove it there 240 volt so easy to test https://www.google.co.uk/search?sou...BB2d3cy13aXo&sclient=psy-ab#spf=1587841935640

 

[malcolm]

If both valves have stopped working more likely to be the signal. Weird having 2 tanks.

It's possible to fit new motorised heads to the newer versions of the valves (last 10 years?) but for older ones you have to replaace the whole valve or be a bodge artist like me and adapt to fit.

Override is kind of fine - the temperature cutout won't work and stop the heating triggered by central heating, but there shouldn't be a lot of central heating this time of year. I'm not a real plumber.

 

[dobbslc]

@Kayos it's a mahoosive thatched cottage on an oil boiler! I don't want to get too involved with it hence the question is it safe to leave the valve overridden for the time being?
I'm wondering if one valve had failed and they didn't notice as the water was still hot and now the second has packed up?
I wouldn't know where to start draining down this system to work on it

 

[dobbslc]

@brightspark it was a round one with orange wires.
The other valve on cylinder 2 was totally different though.

 

[brightspark]

£350 plus vat for 1, needs a full drain down, fill up, new chemicals plus messing about firing it up. If it goes well its half a day if it doesn't it could well be a full day. With 2 cylinders its unlikely to be a 1 bedroom flat

Get it wrong and it will cost much much more than £500

my mates went told him how to test it and it needed a complete new one as the valve had seized up he got a new one for 45 quid drained off fit new one refilled with inhibitor and away he went. 2 hours work he is a joiner . with a bit of guidance a monkey can do them

 

[Kayos]

my mates went told him how to test it and it needed a complete new one as the valve had seized up he got a new one for 45 quid drained off fit new one refilled with inhibitor and away he went. 2 hours work he is a joiner . with a bit of guidance a monkey can do them

If it all goes to plan, last time someone had a go then called me he was stood in 2 inches of water by the time I got go him

 

[brightspark]

@brightspark it was a round one with orange wires.
The other valve on cylinder 2 was totally different though.

its a 14 quid job then and an hours work to replace it. I do em all the time been doing y and s plan for the last 50 years

 

[brightspark]

If it all goes to plan, last time someone had a go then called me he was stood in 2 inches of water by the time I got go him

bet u were rubbing your hands 80 quid callout

 

[Kayos]

bet u were rubbing your hands 80 quid callout

Plus vat

 

[brightspark]

if its on override manual it wont work on the cylinder stat but will cut off when up to temperature on the boiler thermostat

 

[voipio]

Where do the hot water draw-offs for the two cylinders go? Are they in parallel? Just trying to understand the logic behind the setup.

 

[Kayos]

Where do the hot water draw-offs for the two cylinders go? Are they in parallel? Just trying to understand the logic behind the setup.

Just used for more hot water, usually do it to heat up quicker than one massive one

 

[pedrobedro]

Ours is gravity and when it wasn't working it was an airlock in the coil.

 

[Morrisman]

£350 plus vat for 1, needs a full drain down, fill up, new chemicals plus messing about firing it up. If it goes well its half a day if it doesn't it could well be a full day. With 2 cylinders its unlikely to be a 1 bedroom flat

Get it wrong and it will cost much much more than £500

I’m so glad I still pay £19.75 a month for British Gas Homecare. It’s almost guaranteed I’ll never need them..... as long as I keep paying it.


The week I cancel it, well, we all know how that works.

Moved house last month, they come out immediately to do a full boiler service and system check, couple of hours, knowledgable friendly guy.

 

[waddycall]

The motorised valves have micro switches in them to control the boiler when in hot water mode. Opening a valve manually often fails to push the valve far enough to activate the micro switch. If that’s the case then the overridden cylinder will only get hot when the heatings on.
Have a look at S plan wiring diagrams. The brown and blue are the supply to the motor and orange and grey go to the micro switch. If there’s power on the brown then the motors probably had it. Swapping a motor is easy. Depending on the valve they usually come with some crimp connectors so you can just cut the wires inside the valve and connect the new motor onto them.
Sometimes the valve head mechanism gets jammed and the head needs to be replaced. Sometimes the valve internals jam and the entire valve is replaced.
Leaving a hot water motorised valve open is unlikely to cause any issues but you should probably bear in mind that as it controls the supply of heat to the cylinder it’s considered a safety device especially if the cylinders are unvented (no tanks in loft). The boiler thermostat will limit the temperature but the hot water may be significantly hotter. To comply with regs there must be a high limit temperature cut out and on an S plan system the two port valve controlled by the cylinder stat/limit stat is what takes care of this.