Hot water cylinder controls/timer buzzing/humming noise

[ian48]

Hi

I'm hoping someone out there can help me.

I have the following set-up which whilst I've never fully understood has always worked fine and energy bills have been low so not been fussed!

Recently though the timer in the airing cupboard next to the hot water cylinder has been making a buzzing sound intermittently.

Right, so downstairs there is the boiler and a programmer (Landis & Gyr RWB200). Upstairs in the airing cupboard is a hot water cylinder (believed to be indirect based on web diagrams, looking at pipes etc) which has a Honeywell thermostat and an electric immersion on it. Next to it is this second timer unit - a Randall ET009 "heatswitch" as it says on it. I've not been able to find any instructions for it so assume it is old, although digital. It runs off a fused switch and I am assuming that the cable which runs to the immersion on the cylinder is connected to it at the back (disappears off cylinder into same wall unit is on).

I use the downstairs L&G programmer/timer to set hot water and hot water&central heating and (it sounds bad but...) have mostly ignored the timer in the airing cupboard upstairs as irrelevant as up until now I've only needed to turn the Randall timer on every now and then for the immersion. I can tell it's working as it immediately starts making some noise/heating the water.

So this Randall timer in the airing cupboard has time controls, a manual change button, a red indicator light (although the digital display shows off and on etc) and a big black on/off switch. It's the black switch I use to turn the immersion on.

The buzzing noise seems to be from the timer and not anything else and seems to only occur when the digital display shows "off". I have checked for loose wires etc from the fused switch into the Randall timer but not taken the unit off to check the back). I tried turning it off from the fuse box but discovered that the fused switch it feeds off also powers the shower so the test of using up the hot water by showering and seeing what happens didn't work out.

To get rid of the buzzing I've switched the timer unit off at the fuse box to reset it and not set any of the timings and just left it "on" using the manual change button (but big black switch is off).

A week or so ago I noticed the red light always seemed to be on, which worried me (energy costs) so I tried to make it go away! The noise seemed to start after I played with the time settings to make them match the L&G programmer downstairs (next to boiler). Also, I'd better confess that I can't remember what the time settings were set to before - perhaps it was set to always on. Like I say, as I didn't really understand what the box did I just left it as the previous owners had.

So, after my tinkering/causing problems for myself I am wondering: a) does the timer in the airing cupboard serve any purpose other than as a switch for when we need the immersion on? b) if so, can I (or, let's be honest, DIY competent dad when he is back from hols) just replace it with a switch? or c) am I better off replacing it with a like-for-like timer unit?

Thanks very much for any advice anyone can offer - I can post any photos or extra info as needed.

Thanks again

Ian

 

[Armo74]

Have you had the heating on?
What motorised valve(s) do you have?
It is common to get a buzzing noise from the motorised valve when the synchron motor is holding the valve over in position.
Usually cured when the supply is cut and the valve springs back to its rest position(hotwater only).

 

[picasso]

Just get rid of the timer, your main source of heating/hot water is your gas boiler and the immersion is really just as back up.

 

[ian48]

Thanks to you both.

Only the hot water is on. I tested the central heating about a month ago though ahead of winter months.

I can't find a motorised valve - hopefully I'm not being thick. Hopefully the link below works... I've numbered the pics based on position from top to bottom (1 being top) and named a few.

https://flic.kr/s/aHsk3KQov5

https://flic.kr/s/aHsk3KQov5

Thanks very much

Ian

 

[Armo74]

Do you know where your pump is?
The valve is usually near that.
Best get the electrics looked at.
As said get rid of timer and let boiler heat hot water, immersion only a backup anyway just get it re-wired to a fused spur back to the consumer unit.

 

[ian48]

-Do you know where your pump is?

Both pump and motorised valve and downstairs underneath the boiler. The synchron motor was making a bit of a hum, but sounds like normal operation to me (who obviously knows nothing!), it stopped after about 15 seconds though and went silent. Def nothing like the buzzing noise coming out of the timer next to hot water cylinder (presuming it is that making the actual noise).

Pump is Grundfos and the valve is Honeywell. No model no obvious to me on the valve though.

-Best get the electrics looked at.

I need to get the consumer unit replaced anyway as it is an old box (pull out fuses, no RCDs) so I can get this looked at at the same time.

-As said get rid of timer and let boiler heat hot water, immersion only a backup anyway just get it re-wired to a fused spur back to the consumer unit.

Thanks very much for your help. I'm assuming, but I'd rather check: am I alright to leave the timer set to on constantly (albeit with black switch (presume immersion) set to off) for now to keep the buzzing noise quiet or will is it likely to cost? On the downstairs boiler controls/programmer we have the hot water on from 6am til 9pm so I expect when we go to bed at night the hot water tank is full of heated water as we don't usually use any significant amount of hot water after my daughter's bathtime (6.30ish)...

Thanks again

Ian

 

[ian48]

Haha, forgot to check the valve for noise!

Just went and changed the controls in the upstairs timer (water cylinder one), buzzing started up. Went down to check valve and no noise from that area at all.

Banged my knee on the door frame for my troubles - that's karma for you. ALWAYS READ THE QUESTION PROPERLY, IAN!!

Cheers.

 

[Armo74]

You shouldn't hear a noise from the valve unless you put the heating on anyway.
Turn the immersion timer off altogether you don't need it on if the boiler is heating the hotwater anyway.

 

[Armo74]

Forgot to say, how's the knee

 

[ian48]

-You shouldn't hear a noise from the valve unless you put the heating on anyway.

Ah, OK. Didn't know that obviously! Haha.

-Turn the immersion timer off altogether you don't need it on if the boiler is heating the hotwater anyway.

That's the thing. I can't really. If I turn off the fused switch it kills the power to the shower, but the timer stays on (backup battery?!). Best I can do is have the black switch set to off (which is already never on except when use immersion) and the timer's digital display set to off (i.e. using the manual change button)....but this seems to be when the buzzing occurs.

The other option is to pull the fuse out of the consumer unit at night and put it back in the morning for shower. Or I could have a go at disconnecting the timer completely. As the fused switch doesn't turn it off and I'm clearly not a competent DIYer I'd prefer not to touch it.

Knee is fine thanks. They weirdly seem magnetically drawn to door frames so I'm used to it!