Motorised valve question

[Burnerman]

Its back to the Rayburn really....I need to keep the CH 2 port valve open so that the cooker can cool down at the end of the day.
I set the valve to manual, but I see today that it has moved off its stop and closed off....fair enough.
My question is - can I secure the thing in the open position with say a cable tie or something? I don't want to hurt it.
Thanks for reading
Cheers John

 

[kevplumb]

My question is - can I secure the thing in the open position with say a cable tie or something? I don't want to hurt it. icon_confused.gif

don't see why not

that flamin rayburn is gonna be the death of you

 

[Burnerman]

Hey thanks Kev, I'll tie the thing on fully open.
I don't want to faff around with this heap any more really, but if I did want to keep the MV in the on position electrically, which wire would I fix the live to?
Thanks for the reply - greatly appreciated!
John
PS I seem to have a gift for attracting all of these impossible jobs...other folk just run. I'll file it under 'pottering'
J

 

[stardanny]

is the rayburn gas or solid fuel?

I don't see why you can't control it....? Please explain.

What the make of the valve?


Dan.

 

[Burnerman]

Dan, its been an ongoing problem for months now, and there are numerous posts about it on here.
Its an oil fired Rayburn 499k using a twin Nu Way burner - 1 for heating /dhw, 1 for cooking. I've got these sorted although some of the parts aren't available anymore. Nu Way only supplied Rayburn for 2 years with this unit.
If all of the rads are fully on, 3 don't get hot. I've overcome this by balancing, and trying to control the system bypass (S Type).
However, when the unit shuts down for the night, the hot water in the boiler operates a reset stat - which has to be manually reset. To disperse this hot water, I need to keep the pump running. However, with the boiler off, the CH MV is off too, preventing circulation. Even with the bypass, the boiler water still operates the reset.
Thats it - in a huge nut shell!
John

 

[stardanny]

Hmm, I understand the way it work what you say, had a look at your earlier thread.

My dad's friend, who is a farmer, also have a oil fired rayburn, with gravity DHW with bathroom radiator as a heatsink and pumped heating.

Maybe your is used to be a gravity DHW and pumped heating, been changed into fully pumped system?

The only way to get rid of heat from boiler is to have a heatsink ( radiators ) is to use a pump over run and wire the 2 port valve into pump over run as well so the valve can still be control by room stat and pump over run stat.

Depend on valve model, I'm not sure which wire will switch / open the valve.

Dan.

 

[Burnerman]

Hi Dan and thanks for your input....
I think this system either has been poorly designed or it simply isn't suitable...if the bypass incorporated a rad my problems would be over. It doesn't and there's no possibility of me fitting one.
So, I'll keep the CH MV fully open, and the pump overrun stat will disperse the hot water. I guess the fun will start in the summer when only hot water is required....however all but the bathroom rads have TRVs so that may solve that one. If I keep the boiler stat low it also can cope with this, but the rads simply aren't hot enough. In the past, anything more that half boiler stat setting and the reset button would pop. Judging by the end of the reset button its been pressed a million times too!
I reckon that feeding the MV brown wire with a live will keep the valve open - I just don't want to knack up anything else at the same time!
Cheers John

 

[stardanny]

you can do that.

I've had a rethink, best not to wire the live into MV from overun stat, I can see, if you switch on DHW only calling for heat, it open the DHW MV, in turn, switching on boiler and pump, but with the wire connect to CH MV from over run, will switch on the CH MV as well.

Wire it to switch so you can manual switch on CH MV.

Hope it does not let you down.

Dan.

 

[Burnerman]

Useful thoughts those, Dan.
Cheers mate
John

 

[oilhead]

Have you checked the wiring at the Rayburns wiring centre yet? If this is correct, then test the overheat stat; put the phial into a cup of boiling water and see when it pops. You need to study the Rayburn wiring instructions rather than the honeywell system. There must be thousands of these that do not have a problem.

 

[Burnerman]

Have you checked the wiring at the Rayburns wiring centre yet? If this is correct, then test the overheat stat; put the phial into a cup of boiling water and see when it pops. You need to study the Rayburn wiring instructions rather than the honeywell system. There must be thousands of these that do not have a problem.

I completely agree with you mate...all seems hunky dory as far as I can see.....the only thing recommended by Rayburn is that a rad is used in the bypass to dissipate residual heat - and this I cannot do.
I've renewed the boiler stat, overrun stat and reset stat (all courtesy AGBO) needlessly - but I don't give a stuff about that.
Anyway, the house is cosy, the DHW is hot and there's plenty of it, and the reset button isn't tripping, so I think its probably the best of a bad job.
Cheers John

Edit: Norcon came up with an interesting possibility.....a spring loaded valve, fitted in parallel with the CH MV. That would sort it, I think. J