Hot water cylinder clicking -? Dangerous?

checkincherry

Hi folks - hoping someone out there can pls help with some knowledge!

Got a bit of a shock this morning when the hot water came on at 5.30am. My DD and I were woken up by very loud (enough to wake us both up) clicking noises from the hot water cylinder.
It seems to be coming from the cylinder itself not the various pipes in the airing cupboard and happens when the condensing boiler is on either hot water only or CH setting (I did some tests - after all, what else to do at that time when the alarm isn't due for another 1.5 hrs, but you're wide awake!)

Doesn't seem to happen with the immersion on, only the gas boiler.

Any ideas what it could be? Does it sound dangerous, like I shouldn't leave the HW timer on when I'm out in case something explodes?

The house and CH/HW system is only 5 yrs old.

Help gratefully received - I'm up to changing the odd uPvC window handle or broken flush button but fear this is one for a professional.

Tx
Cherry

MX5huggy

Is your cylinder a unvented one or a traditional vented one (with a cold water tank in the loft)?

cajef

Have you got a two or three port zone valve near the cylinder, sounds like that could be sticking if it is the motor it can be replaced without taking the valve off.

uptheanti

cajef you beat me to it i agree could be 3/2 port

checkincherry

MX5huggy wrote: »

Is your cylinder a unvented one or a traditional vented one (with a cold water tank in the loft)?

Yes, there is a tank in the loft. This is covered in lots of black lagging. Is that a cold water tank?

checkincherry

cajef wrote: »

Have you got a two or three port zone valve near the cylinder, sounds like that could be sticking if it is the motor it can be replaced without taking the valve off.

Hmm- Thanks for your question - don't know if I know the answer. I don't know what the valve is you're describing, so , pls bear with me and I'll try to describe what I can see. There are a lot of pipes in the airing cupboard. Three go in/out of the cylinder:
One running out of the top of the cylinder.
One at the very bottom , which then splits into two, one pipe running up to a junction with another pipe with some sort of "thermostatic"? valve ( well there is a knob on it with numbers up to 7 although I can't seem to turn it all.)That pipe then runs upwards to something that looks like a motor? ( It's burgundy - Grundfos Super Selective written on it and it has an electric cable running from it.)
One in the middle of the tank about the same level as the thermostat ( see, I'm not completely useless, i do recognise somethings - although it does say "thermostat" on it :rotfl:). This pipe runs through a "t-junction" type pipe arrangement with a silver box on one side ( also has a wire running out of it). That pipe runs into the one leading to the "motor", above the "thermostat" junction.

Sorry for not being more clued up. Does this amateur description help?

checkincherry

uptheanti wrote: »

cajef you beat me to it i agree could be 3/2 port

THanks for taking the time - are you and cajef saying it could be the motor making the noise? Is it dangerous to continue running the system do you think, or something that I can get seen to in the next week and still use this to run the hot water.

checkincherry

checkincherry wrote: »

Hmm- Thanks for your question - don't know if I know the answer. I don't know what the valve is you're describing, so , pls bear with me and I'll try to describe what I can see. There are a lot of pipes in the airing cupboard. Three go in/out of the cylinder:
One running out of the top of the cylinder.
One at the very bottom , which then splits into two, one pipe running up to a junction with another pipe with some sort of "thermostatic"? valve ( well there is a knob on it with numbers up to 7 although I can't seem to turn it all.)That pipe then runs upwards to something that looks like a motor? ( It's burgundy - Grundfos Super Selective written on it and it has an electric cable running from it.)
One in the middle of the tank about the same level as the thermostat ( see, I'm not completely useless, i do recognise somethings - although it does say "thermostat" on it :rotfl:). This pipe runs through a "t-junction" type pipe arrangement with a silver box on one side ( also has a wire running out of it). That pipe runs into the one leading to the "motor", above the "thermostat" junction.

Sorry for not being more clued up. Does this amateur description help?

Ok - now done the sensible thing and googled for a picture of two/three port valve - it's the thing with a silver box attached! Yes, I have one of those (3 port) between the middle pipe on the boiler and the "motor". Would that also be responsiblke for my radiators getting hot when the CH is off, but the HW is on?

cajef

checkincherry wrote: »

Ok - now done the sensible thing and googled for a picture of two/three port valve - it's the thing with a silver box attached! Yes, I have one of those (3 port) between the middle pipe on the boiler and the "motor". Would that also be responsiblke for my radiators getting hot when the CH is off, but the HW is on?

If that valve is sticking the motor is constantly trying to move the valve but nothing is happening and motor just clicks all the time, and yes depending on the position it is stuck in it can cause the heating to be on even though the CH is set off.

If the actual valve is stuck then the system will have to be drained down to replace it.

checkincherry

cajef wrote: »

If that valve is sticking the motor is constantly trying to move the valve but nothing is happening and motor just clicks all the time, and yes depending on the position it is stuck in it can cause the heating to be on even though the CH is set off.

If the actual valve is stuck then the system will have to be drained down to replace it.

Thanks cajef. Cost of the valve looks abo £50-£60 with VAT. Is it likely to be a "Big" (aka expensive) job to get a plumber to do the replacing? like hours and hours of work? I don't know how to drain the system and as there's wires involved on the motor/silver box thing, I think I shouldn't do this myself.

Again, is this problem likely to be dangerous pls. Apart from being annoying, is something likely to explode? ( not trying ot be melodramatic, just trying to avoid an even bigger problem.)

cajef

Depending on your DIY skills it is possible to check the valve yourself, firstly switch the power off to the boiler and central heating system, if you take the cover off the valve (the silver box:)) you will see the motor, this is held on with a couple of screws remove these and the motor just lifts off you will then see the head of the valve, check the position of the valve then you can put it back in the same position so when you put the motor back on it aligns with the valve head, you should be able to turn this with a small spanner or screwdriver to check if the valve is stuck, sometimes this will free the valve if it is sticking.

If the valve moves freely then it is possibly the motor sticking which can be replaced without removing the valve, if it is the valve then you will probably need a plumber as to replace the whole valve the system will need draining down, to change the actual valve is only half an hours work it is draining down and refilling plus checking for leaks and air locks etc. which will take the time, ask for estimates if you need a plumber.

You can still use the system with it clicking it will not blow up or anything, but it is not recommended to leave it too long before getting it sorted.