Help with 'what is this' please

twopenny

So I have been getting an alarming noise from the airing cupboard where the timer for the heating is. It's a Drayton Duel Channel Programmer.

It is a loud buzzing noise when the hot water is on.

A gas fitter on the premises changed that timeer it for one with a timing I prefered and, on switching on, when he heard the noise he said it was coming from the gizmo attached to the copper pipe (photo below) and pushed it to the right slightly and the noise stopped. He suggested everything was ok, he could change it if I liked but to save my money and leave it.

The noise began again the next day so I gave it a shove and it stopped. Gradually it started the following day so I shoved it harder and for now at least the noise has stopped.

Please can you explain what it is and is it likely to be a loose connection, a worn out 'whatever it is' or am I being over anxious and should just give it a shove if the noise starts again.

It took 3mts to get someone to call and should it be dodgy in the slightest I'd rather get it sorted than save money. A colleague had a fire start in their airing cupboard and I'm twitchy.

Ebe_Scrooge

The "gizmo" is what they call a motorised valve.  In simple terms, the boiler chucks out heat, the motorised valve diverts the heat to either the central heating, the hot water tank, or both, depending on what your timer/programmer is telling it to do.

Motorised valves do "go".  Sometimes it's just a case of it needing a good clean, but sometimes the motor can fail.  I wouldn't be worried about it causing any danger as such, but it would be inconvenient if it failed - you'd be left with either no heating or no hot water.

If it's sticking, then by giving it a shove you're freeing it up and allowing the valve to move to where it should be.  If it were me, I'd be tempted to get the cover off and give it a clean - after isolating it from the power supply.  If you're not confident in doing that, then any decent heating engineer should be able to do it for not much money.  If it does turn out to be kaput or on its way out, they're not a huge amount of money to replace.  Hope this helps.

tacpot12

The thing is a Drayton Mid Position Actuator. (It's written on it.) The buzzing is likely to be a worn gear within the actuator, not an electrical fault. I expect that the motor is spinning its output gear, but the gear is slipping on the arm that it drives. I would get it changed asap. The part is about £70, so not cheap, but worth replacing to avoid problems in future. It is a ten minute job if your heating system can be isolated electrically, you can even do it yourself if you know how to test that the heating system is electrically isolated and have the tool to do so. 

twopenny

Excellent thank you!

Of course finding a heating engineer is a whole different matter. The one who came is good at his job but a bit random. He only wants to service boilers, doesn't like being in peoples houses (though he spent an hour in my kitchen drinking tea and telling me about his achievements etc) and that this would be expensive so my alert is up.

So far, so good. It's the hot water that seems to kick it off and I have a seperate immersion. Though the element or thermostat is in need of a checking as since the tank was replaced the water is overheating on that. It;s the joy of moving to a place that was never used since building 15yrs ago and a pandemic.

I'm trying to remain calm and call on my zen.

FreeBear

twopenny said: So far, so good. It's the hot water that seems to kick it off and I have a seperate immersion. Though the element or thermostat is in need of a checking as since the tank was replaced the water is overheating on that.

There should be a thermostat on the HW tank - Turn it down to around 55°C and that should fix the overheating. 55°C is also hot enough to kill bacteria such as Legionella as long as the temperature is maintained for a few hours.

twopenny

Tacpot, our posts crossed. Thanks for mentioning the price and time. That will help with negotiations - which is a laugh. You take who you can get at the moment and keep your fingers crossed.

FreeBear, thanks for the bonus answer. It's on 60 at the mo and fine if I remember to turn it off after 15mins or so but forgot one day and it was scalding. Hopefully I won't have to resort to it for some time.

Belenus

There are some new units listed on eBay here for a lot less than the list price of £70.

There are also used units even cheaper but I would advise against them as they may well also be faulty or fail quickly.

It is a snap fit onto the actual valve. From what I can see you would need to wire the 5 wires yourself into the boiler controller. That should be straightforward for someone with basic DIY skills as all you need to do is copy the colour coded wire connections of your faulty unit but it is possible that access may be difficult.

And it is essential that the electricity is fully isolated as they operate at 230 volts.

Buying on eBay is a bit riskier than buying from a local plumbers merchant or Screwfix as you have less of a comeback if the unit develops a fault in the first year or so.

I bought a similar actuator last year brand new for half the list price and it has been fine. Mine has a plug in wiring loom with a small connector that plugs into the actuator so I did not need to do any rewiring or access the boiler controller.

twopenny

That's good to know Belenus. You never know when the info will be useful.

I'll do a plug, socket or light fitting but I'll leave this to someone who knows what they are doing.

I have a random collection of diy skills, this isn't one of them.

I always feel much happier when I understand what's going on, what the options are so that I don't get ripped off.

My old home was so much simpler than this one.

Bendy_House

twopenny said:

I'll do a plug, socket or light fitting but I'll leave this to someone who knows what they are doing.

I have a random collection of diy skills, this isn't one of them.

I'm not going to suggest you do this job, 2'penny, but I'll just say that it isn't technically any more difficult than these. It is very like wiring a plug - you unscrew a terminal, slip in the wire, and tighten the screw again.

Only there's 5 wires, and it's inside a box with lots of others...

Someone - I think on this forum - suggested a nice tip for this job; the 5 wires are colour-coded, so POWER OFF and snip the old wires an inch from their terminals in the wiring box, leaving a section with the coloured insulation behind. You then swap the wires one at a time - remove the old inch of 'orange' and slip in the new 'orange'. Repeat.

I'd also recommend buying the whole unit - head and valve - as you can often get them for little more than just the cost of a head. Just replace the head for now, but leave the valve body in the airing cupboard so that a plumber can swap it as part of any future job that involves a drain-down. It'll add only 15 minutes to whatever else they are doing.

Or, the head-swap is an easy well-under-one-hour task for a sparky. If you go this route, ask them to check the operation of the cylinder 'stat, because it sounds as tho' it ain't working properly.

You can test the cylinder 'stat yourself without going near 'electrics'. First, just try turning the temp control on it up and down so you hear 'clicks' each time. What temp is in the middle of these clicks (it'll click in a slightly different position depending on whether you are going upski or downski, but it'll be in the same ballpark). Does this temp correspond with what you think the water temp is? Ie, if it's at ~60oC, the tap water should be 'ouch' hot, around 70-ish degrees (the water coming out the top of the cylinder will be noticeably hotter than that at the 'stat position). If the water is 'scalding', then the 'stat should really be clicking at, ooh, 70oC plus. If you've had a long shower and the water is just 'hot', then the 'stat will likely be at ~50oC. So does it 'seem' correct?

The next test is more conclusive. Turn your room stat up until your CH is on. Turn the cylinder 'stat up until it goes 'click' - ie your DHW is also on. Ok, look at the black lever on the side of that Drayton head. It'll be marked either W, M, H (Water, Mid, Heating) or A and B at each end, with a gap in the middle.

Ok, with BOTH the DHW and CH on, that lever should be in the middle. Now turn the cylinder 'stat down until it 'clicks'; that lever should quickly move to the B or H position.

twopenny

Good grief Bendyhouse, that's a lot for an old lady at this time of day. I appreciate your time and detail and some of it registers.

The shower isn't a problem, I still haven't got a bathroom!

Only a tiny electric shower in a laughingly called 'en suite'

I will arrange the laptop near the airing cupboard at the weekend and check through what you have said re testing.

The water temperature to be 'ouch' at 60 wasn't what I expected so maybe I'm wrong about the thermostat fingers crossed.  I'll investigate that.

And I don't have a room thermostat. Just TRVs which suits as things stand and because of when it was built I'm allowed.

At the moment half an hour in the morning by gas gives me a hot tankful for the day as I use so little. I just want reliable back up due to previous experience of being without a gas boiler during both lots of the Beast from the East.

Bendy_House

Fair do's, 2'penny.

To do the second test, the boiler should be on for CH too, so that the 'head' moves as described.