Anyone know what these boxes are?

[sy677]

What are the 2 silver metal boxes attached to the pipes at the front/bottom of the photo. I'm guessing thermostats.

Basically, when I switch on the hot water, there is a loud clicking/buzzing sound coming from one of them. Should I get them replaced? The hot water and heating still works.

boiler

• sy677
• 7 Sep 2015

 

[Dan Robinson]

They're zone valves.

 

[leakydave]

If they open and close as required I would try and live with it.

 

[sy677]

Thanks Dan/Dave. So not worth getting someone to replace or upgrade anything?

 

[Dan Robinson]

Probably not.

Depends how much the buzzing and ticking annoy you. Eventually whatever one is doing it will conk out. Not a major job to change.

 

[leakydave]

I can't see any kind of auto bypass though on your S-plan

 

[gigz]

I can't see any kind of auto bypass though on your S-plan

+1

 

[sy677]

S-plan? Auto bypass? That sounds important. Time to get someone in then I guess...

 

[JohnD]

they appear to be 2-port valves, which have an electric motor in the head to open and shut them. If one of yours is noisy then the gearing, or perhaps the switch, is worn out and the valve may not be working correctly. It will probably get worse rather than better. If it is just the motorised head it can be swapped without draining down, but the internal ball also wears out after 20 years or so.

You have an Unvented Cylinder which runs at relatively high pressure. It is an excellent system and is fitted with various safety devices. You should have it inspected and serviced about once a year by a person who has the Unvented qualification (G3 ticket). It is fairly common but you cannot assume that all plumbers and heating engineers are qualified, so ask. You can probably have it done in the same visit as your annual boiler service.

further info
http://www.screwfix.com/c/heating-plumbing/motorised-valves/cat831028
https://www.tradeskills4u.co.uk/courses/unvented-courses

BTW those copper pipes ought to be insulated, you can do that yourself with Climaflex or similar at low cost. Use the thick "water regs" lagging if it will fit.

The wiring is rather untidy.

 

[sy677]

Thanks John, that's really helpful. Much appreciated.