I know nothing about central heating systems or their associated controls
but I noticed that the boiler wasn't heating the water and so we've had to
revert to the immersion heater to get hot water.

The three pipes connected to this Drayton MA1 motorised valve are all cold
to the touch but the MA1 itself is quite hot if you touch it, which would
suggest to me that there's some sort of electrical fault with it - maybe a
failed motor?

Screwfix sell replacement motors @ £23.99 or the whole thing for just
under £80 but is there any way to test first before I chuck my hard-earned
at it?

Customer <none@ab.com> wrote:
> I know nothing about central heating systems or their associated controls
> but I noticed that the boiler wasn't heating the water and so we've had to
> revert to the immersion heater to get hot water.
>
> The three pipes connected to this Drayton MA1 motorised valve are all cold
> to the touch but the MA1 itself is quite hot if you touch it, which would
> suggest to me that there's some sort of electrical fault with it - maybe a
> failed motor?
>
> Screwfix sell replacement motors @ £23.99 or the whole thing for just
> under £80 but is there any way to test first before I chuck my hard-earned
> at it?

There's usually a slider which you can use to move the valve
manually. On this pic I think it's the one marked W-M-H:
https://www.wickes.co.uk/Drayton-22mm-3-Prt-Mid-Pos-Vlv-MA1-679-3/p/228406

When you slide that, you can feel the resistance from when the motor is
engaged and when it isn't.

I'd try experimenting with that, with the motor both powered and unpowered,
and see if you can tell if the motor is providing any force.

You can also set it to the hot water side (I'm guessing that's 'W' but maybe
somebody plumbed it backwards) and confirm that the boiler does heat the
water successfully, pointing to the valve being the problem. If manually
setting 'W' gives you hot water and 'H' gives you heating (or vice versa) it
points to the valve being a problem.

Although I think a mid position valve shouldn't have a closed position, so
unless it's very broken I'd be suspecting the pump. If you move the valve
manually and still neither of the pipes get hot, that starts to point more
towards the pump (or upstream towards the boiler).

Theo

On Sat, 22 Jul 2023 12:47:33 +0100, Theo wrote:

> Customer <none@ab.com> wrote:
>> I know nothing about central heating systems or their associated
>> controls but I noticed that the boiler wasn't heating the water and so
>> we've had to revert to the immersion heater to get hot water.
>>
>> The three pipes connected to this Drayton MA1 motorised valve are all
>> cold to the touch but the MA1 itself is quite hot if you touch it,
>> which would suggest to me that there's some sort of electrical fault
>> with it - maybe a failed motor?
>>
>> Screwfix sell replacement motors @ £23.99 or the whole thing for just
>> under £80 but is there any way to test first before I chuck my
>> hard-earned at it?
>
> There's usually a slider which you can use to move the valve manually.
> On this pic I think it's the one marked W-M-H:
> https://www.wickes.co.uk/Drayton-22mm-3-Prt-Mid-Pos-Vlv-MA1-679-3/p/
228406
>
> When you slide that, you can feel the resistance from when the motor is
> engaged and when it isn't.
>
> I'd try experimenting with that, with the motor both powered and
> unpowered, and see if you can tell if the motor is providing any force.
>
> You can also set it to the hot water side (I'm guessing that's 'W' but
> maybe somebody plumbed it backwards) and confirm that the boiler does
> heat the water successfully, pointing to the valve being the problem.
> If manually setting 'W' gives you hot water and 'H' gives you heating
> (or vice versa) it points to the valve being a problem.
>
> Although I think a mid position valve shouldn't have a closed position,
> so unless it's very broken I'd be suspecting the pump. If you move the
> valve manually and still neither of the pipes get hot, that starts to
> point more towards the pump (or upstream towards the boiler).
>
> Theo
Thanks Theo, that's great.

In article <u9ge5a$3pie8$1@dont-email.me>, Customer <none@ab.com> wrote:
> I know nothing about central heating systems or their associated controls
> but I noticed that the boiler wasn't heating the water and so we've had
> to revert to the immersion heater to get hot water.

> The three pipes connected to this Drayton MA1 motorised valve are all
> cold to the touch but the MA1 itself is quite hot if you touch it, which
> would suggest to me that there's some sort of electrical fault with it -
> maybe a failed motor?

> Screwfix sell replacement motors @ £23.99 or the whole thing for just
> under £80 but is there any way to test first before I chuck my
> hard-earned at it?

The motor is held on to the valve by two screws. Remove it and see if you
can turn the valve. That should indicate whether it's the valve at fault.

--
from KT24 in Surrey, England - sent from my RISC OS 4té
"I'd rather die of exhaustion than die of boredom" Thomas Carlyle

On Sat, 22 Jul 2023 12:00:02 +0000, charles wrote:

> In article <u9ge5a$3pie8$1@dont-email.me>, Customer <none@ab.com> wrote:
>> I know nothing about central heating systems or their associated
>> controls but I noticed that the boiler wasn't heating the water and so
>> we've had to revert to the immersion heater to get hot water.
>
>> The three pipes connected to this Drayton MA1 motorised valve are all
>> cold to the touch but the MA1 itself is quite hot if you touch it,
>> which would suggest to me that there's some sort of electrical fault
>> with it - maybe a failed motor?
>
>> Screwfix sell replacement motors @ £23.99 or the whole thing for just
>> under £80 but is there any way to test first before I chuck my
>> hard-earned at it?
>
>
> The motor is held on to the valve by two screws. Remove it and see if
> you can turn the valve. That should indicate whether it's the valve at
> fault.

Thanks Charles, much appreciated.

On Sat, 22 Jul 2023 11:22:18 +0000, Customer wrote:

> I know nothing about central heating systems or their associated
> controls but I noticed that the boiler wasn't heating the water and so
> we've had to revert to the immersion heater to get hot water.
>
> The three pipes connected to this Drayton MA1 motorised valve are all
> cold to the touch but the MA1 itself is quite hot if you touch it, which
> would suggest to me that there's some sort of electrical fault with it -
> maybe a failed motor?
>
> Screwfix sell replacement motors @ £23.99 or the whole thing for just
> under £80 but is there any way to test first before I chuck my
> hard-earned at it?

The MA1 I replaced didn't need any screws to remove the motor head. You
slide a catch on one side and it lifts off. I would turn off the power to
the boiler first.

Now see the the valve stem rotates or is jammed. It doesn't move far (90
degrees or even less). I managed to free mine with WD40 and the gentle
application of pliers.

The jam was caused by a failed head, so I got a new one. Wires are one to
one, but I cheated (see below). I decided I'd replace the whole thing
anyway. BTW, it gets hot in use because the motor is permanently driving
against an end stop in some positions. I decided it was probably time to
replace it.

You can test the head while it's off by selecting hot water, heating or
both and watching it (hopefully) rotate the boss that fits onto the shaft.
I would not bother with just the motor.

The way I fitted it (power OFF) was to cut the cable to the wiring centre,
and fit a plug to the cable on the new head and a socket to the cable from
the wiring centre. And it's less work when you need to replace it again.

I used:

https://www.amazon.co.uk/gp/product/B00BXEYUVC/

and

https://www.amazon.co.uk/gp/product/B07FZQ17W7/

(this is the intended use for that plug and socket)

--
My posts are my copyright and if @diy_forums or Home Owners' Hub
wish to copy them they can pay me £1 a message.
Use the BIG mirror service in the UK: http://www.mirrorservice.org
*lightning surge protection* - a w_tom conductor

On Sat, 22 Jul 2023 13:45:31 +0000, Bob Eager wrote:

> On Sat, 22 Jul 2023 11:22:18 +0000, Customer wrote:
>
>> I know nothing about central heating systems or their associated
>> controls but I noticed that the boiler wasn't heating the water and so
>> we've had to revert to the immersion heater to get hot water.
>>
>> The three pipes connected to this Drayton MA1 motorised valve are all
>> cold to the touch but the MA1 itself is quite hot if you touch it,
>> which would suggest to me that there's some sort of electrical fault
>> with it -
>> maybe a failed motor?
>>
>> Screwfix sell replacement motors @ £23.99 or the whole thing for just
>> under £80 but is there any way to test first before I chuck my
>> hard-earned at it?
>
> The MA1 I replaced didn't need any screws to remove the motor head. You
> slide a catch on one side and it lifts off. I would turn off the power
> to the boiler first.
>
> Now see the the valve stem rotates or is jammed. It doesn't move far (90
> degrees or even less). I managed to free mine with WD40 and the gentle
> application of pliers.
>
> The jam was caused by a failed head, so I got a new one. Wires are one
> to one, but I cheated (see below). I decided I'd replace the whole thing
> anyway. BTW, it gets hot in use because the motor is permanently driving
> against an end stop in some positions. I decided it was probably time to
> replace it.
>
> You can test the head while it's off by selecting hot water, heating or
> both and watching it (hopefully) rotate the boss that fits onto the
> shaft.
> I would not bother with just the motor.
>
> The way I fitted it (power OFF) was to cut the cable to the wiring
> centre,
> and fit a plug to the cable on the new head and a socket to the cable
> from the wiring centre. And it's less work when you need to replace it
> again.
>
> I used:
>
> https://www.amazon.co.uk/gp/product/B00BXEYUVC/
>
> and
>
> https://www.amazon.co.uk/gp/product/B07FZQ17W7/
>
> (this is the intended use for that plug and socket)

Brilliant, cheers Bob.

That sounds like a naff way to design a motorised valve, one might have
imagined some kind of microswitch to cut the current at either end of
travel.
Brian

--

--:
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...
briang1@blueyonder.co.uk
Blind user, so no pictures please
Note this Signature is meaningless.!
"Customer" <none@ab.com> wrote in message
news:u9h250$3ssmc$1@dont-email.me...
> On Sat, 22 Jul 2023 13:45:31 +0000, Bob Eager wrote:
>
>> On Sat, 22 Jul 2023 11:22:18 +0000, Customer wrote:
>>
>>> I know nothing about central heating systems or their associated
>>> controls but I noticed that the boiler wasn't heating the water and so
>>> we've had to revert to the immersion heater to get hot water.
>>>
>>> The three pipes connected to this Drayton MA1 motorised valve are all
>>> cold to the touch but the MA1 itself is quite hot if you touch it,
>>> which would suggest to me that there's some sort of electrical fault
>>> with it -
>>> maybe a failed motor?
>>>
>>> Screwfix sell replacement motors @ �23.99 or the whole thing for just
>>> under �80 but is there any way to test first before I chuck my
>>> hard-earned at it?
>>
>> The MA1 I replaced didn't need any screws to remove the motor head. You
>> slide a catch on one side and it lifts off. I would turn off the power
>> to the boiler first.
>>
>> Now see the the valve stem rotates or is jammed. It doesn't move far (90
>> degrees or even less). I managed to free mine with WD40 and the gentle
>> application of pliers.
>>
>> The jam was caused by a failed head, so I got a new one. Wires are one
>> to one, but I cheated (see below). I decided I'd replace the whole thing
>> anyway. BTW, it gets hot in use because the motor is permanently driving
>> against an end stop in some positions. I decided it was probably time to
>> replace it.
>>
>> You can test the head while it's off by selecting hot water, heating or
>> both and watching it (hopefully) rotate the boss that fits onto the
>> shaft.
>> I would not bother with just the motor.
>>
>> The way I fitted it (power OFF) was to cut the cable to the wiring
>> centre,
>> and fit a plug to the cable on the new head and a socket to the cable
>> from the wiring centre. And it's less work when you need to replace it
>> again.
>>
>> I used:
>>
>> https://www.amazon.co.uk/gp/product/B00BXEYUVC/
>>
>> and
>>
>> https://www.amazon.co.uk/gp/product/B07FZQ17W7/
>>
>> (this is the intended use for that plug and socket)
>
> Brilliant, cheers Bob.

On 23/07/2023 10:47, Brian Gaff wrote:
> That sounds like a naff way to design a motorised valve, one might have
> imagined some kind of microswitch to cut the current at either end of
> travel.
> Brian

Small synchronous motors have no problem with being stalled. It makes
for a very simple design, with the motor moving the valve until it hits
the end stop and returning back under the force of a spring when
de-energised.

Cutting the power at the end of travel would required removal of the
spring and a more complicated control, needing to power the motor back
again when required.

On 23/07/2023 11:17, SteveW wrote:
> On 23/07/2023 10:47, Brian Gaff wrote:
>> That sounds like a naff way to design a motorised valve, one might have
>> imagined some kind of microswitch to cut the current at either end of
>> travel.
>>   Brian
>
> Small synchronous motors have no problem with being stalled. It makes
> for a very simple design, with the motor moving the valve until it hits
> the end stop and returning back under the force of a spring when
> de-energised.
>
> Cutting the power at the end of travel would required removal of the
> spring and a more complicated control, needing to power the motor back
> again when required.
>

+1
A fairly simole design and if its good enough to be working in a
million+ homes don't fix a design that isn't broken

--
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