Motorised valve

[cbrAndy]

Hello all

Got a prob with my three way valve Cct, when the heating comes on the valve lever rises as normal,...however when the heating goes off the lever sometimes stays up (still energised). If I flick the hot water on then off the lever will then come down and stay down until heating is on again.

It doesn't always do it, but up to now its got through three motors!

The motor is Siemens RMH and the programmer and thermostat is Honeywell.

Any advice appreciated......Ta.....Andy

 

[SimonG]

Check the actual valve, take the head off and spin the valve by hand, sounds as though its jamming if it's burnt out three heads. Don't forget some inhibitor when you refill after changing valve, it helps to lubricate it.

 

[cbrAndy]

Checked the valve before putting new head on and it was moving freely :confused5:

 

[WHPES]

You don't need to change the entire actuator, just the synchronous motor, which is a fraction of the cost of an actuator.

 

[tamz]

The valve will stay in the CH position if the cylinder stat turns the hot water off before the heating. It is held there by being powered by the grey wire (HW off). This is normal.
If the HW is still on when the CH turns off (valve in mid position) it will return to closed.
Siemens valves are not exactly the best but as WHPES said you can buy synchron motors for about a tenner.

 

[kimbo]

If this is the plastic headed valve you cant change the synchron motor because they have an extra long cog on it, I did change one recently with the standard cog and it wont work properly. All the workings are in plastic and you will find they jam. Siemmens have now changed this valve for a metal headed one which is much better so if you have the plastic headed one chuck it away and fit a complete new valve

 

[cbrAndy]

The valve will stay in the CH position if the cylinder stat turns the hot water off before the heating. It is held there by being powered by the grey wire (HW off). This is normal.
If the HW is still on when the CH turns off (valve in mid position) it will return to closed.
Siemens valves are not exactly the best but as WHPES said you can buy synchron motors for about a tenner.

I think you've sussed it for me :icon14:

Timings:-
HW 6.30am - 7.30am
CH 6.00am - 8.20am

HW 4.30pm - 7.30pm
CH 4.30pm - 9.30pm

The HW always switches off before the CH, therefore the valve will stay in the CH position, yes?
Just seems strange that the valve stays there energised (using electricity) all the time, thought this was the reason the motor burns out?

 

[fuzzy]

valve always defaults to hot water, not sure if it uses energy in this state or the spring forces it over when not in use

 

[cbrAndy]

valve always defaults to hot water, not sure if it uses energy in this state or the spring forces it over when not in use

Bugger!...now I am confused :sad3:

The head is hot when in CH position and cold in HW, so I presume the spring brings it back to HW ?

 

[cbrAndy]

can anybody clarify,........ please!

 

[tamz]

It springs back on HW only. Although power is being applied to the orange wire nothing is happening with the valve and no power is on the motor.

Turn on the CH alongside the HW power is applied to the white wire which moves the motor. When it reaches mid position it hits a microswitch which then diverts the power through a diode and resistor and sends a reduced power to the motor which is just enough to hold the motor open against the spring but not enough to advance it any further.

During this time, if theHW stat shuts off then the cylinder stat sends power down the grey wire which powers the motor with 240v and advances it right across to CH position.

If the programmer then switches off CH and HW, the valve will remain in the open position powered from the HW off to the grey wire.
If the cylinder stat had opened again before the programmer switched off the valve would spring return to its default position with no power to the motor.

I think i have got that right:49:

 

[cbrAndy]

Ooookay, (way over my head ....lol) all I wanna know is if its working properly from the info I've provided or not, or if you need more info?

Ta!

 

[fuzzy]

when i say hot water i mean the ball goes over to heating to block it leaving hot water only

 

[tamz]

all I wanna know is if its working properly from the info I've provided or not, or if you need more info?

Ta!

It is working as it should.

 

[cbrAndy]

Thanks tamz,......

 

[fuzzy]

so its all working fine now? did you swap the valve?

 

[cbrAndy]

A new head was fitted, and is working as tamz described

 

[RobertLB]

My CH goes off last so have noted that the valve head is still energised - Honewell say that this is correct as valve will always stay in the last position used. Nonetheless it gets very hot and whilst motor has not burnt-out I am concerned that this may be a potential fire risk. Also noted that when in this state I get about 28volts on the orange wire. Is this all correct, and can I just shut the airing cupboard door and forget all about it

 

[cbrAndy]

Yours is operating the same as mine and should be fine, mine was burning out because the head is plastic and over time it warps and jams the motor!.

I am also a bit wary about the motor being energised all the time, slightly about the heat (cos they do get very hot) and also they must be using power all the time!