No power to 2 port valve

[beesley121]

Hi guys,

still trying to get my head around the wiring on s plan and y plan systems

got called to a job yesterday, its an unvented cylinder and don't have my ticket for unvented so need to know if they need to get someone in that has there unvented ticket

anywsy prob is, the whole system is on a s plane, 2 x 2 port valves next to unvented cylinder. Ch 2 port valve is working as it should. Hw 2 port valve however has I power going to it when the timeclick is turned on.

not sure if this is down to the thermostat on the unvented cylinder or the time clock is faulty.

When putting the 2 port valve into the manual postion, the boiler still does not fire up. Should this not over ride it? The cylinder is a megaflo, all the electrical a are behind a grey cover. Not sure which is what so I can rule out the thermostat on the cylinder

 

[SafeGasInstall]

hi Beesley121 ,

probably better off passing job to some one else and learn from when job gets done at the same time ,
sequence of work is :
1.programer
2.stat
3.motorised valve
4.pump
5.boiler

 

[AlexGas]

Also, there are could be installation issues with the system. As you say, without the ticket you won’t be able to spot them.

 

[SafeGasInstall]

Is it a new install , is the over heat stat wired in correctly ???

 

[mountainman]

Also, there are could be installation issues with the system. As you say, without the ticket you won’t be able to spot them.

I agree.

 

[diamondgas]

Hi Beesley .. You don't need unvented to work on the 'S'Plan.... I'd like to know how comfortable you are at electrical fault finding. The motorised valve has a permanent live and a switched live from external controls. The Switched live drives the motor on the valve, Brown usually Check that you have 240v there, if not then the fault lies further up stream eg cylinder stat or programmer...! If you do then it the valve synchron motor/head!

 

[lame plumber]

being that one of the motorised valves is integral to the safety of the unvented cyl, you do have to be g3 to work on it in the eyes of the law.

 

[beesley121]

I'm ok testing wise, just have to get my head around how it works. It's hard to type exactly what I'm thinking cos it would just take too long. All I want to do is work out the part Thats at fault. If it's something to do the unvented cylinder then I will pass the job on, if not, I'll sort it myself.

im sure i seen a wiring diagram once that shown the flow of current to the stat, 2 port valve , boiler etc. anyone point me in that direction

as for this job, there is nothing wrong with the 2 port valve, resistance checks out, it's just thers no power getting to the motor full stop

 

[Ermintrude]

Cut out or stat on cyl G 3 bod req!

 

[SafeGasInstall]

Pls see post 2 for sequence of work ! But again you need to be explain in person to understand it !

 

[firemant]

Go to honeywell site. You will find wiring diagrams, which will help a long way to understanding the sequence.:https://www.google.co.uk/search?q=h...=ie7&rlz=&gws_rd=cr&ei=IKt4UqSdHYSRhQeAyoCYDA