Potterton wiring problems.

[markspark]

Hi hope you can help i have a potterton suprima 30 boiler, ep2002 controller, ptt2 cylinder stat and a drayton room stat on a fully pumped system. The problem i was having was that when my time clock was OFF the boiler started up on its own , i suspected the clock so i changed it for a new one but it still happened so ive now changed the clinder stat and found out it has a boost button to start the boiler when the clocks off for a tank of hot water, the only problem was that when the boiler started up the pump didnt run so i got 'water hammer' pretty bad and so shut it off. Traced the wiring and found it was completely wired wrong so fettled that but the drawings show the pump connected via the 'pump' connection inside the boiler were as it was wired via just the CH switch before (hence the pump not running when just the HW on) is this right ????should the pump be connect via the boiler ???? ill attempt to upload the wiring pic.
Thx for any help.
Regards Mark.

Untitled

• markspark
• 29 Sep 2009
• 2

 

[powell30]

Suprima boilers have a live and switch live. This will run the pump. Get on the baxi web site and download the installation doc for the boiler, this will show how it should be wired

 

[markspark]

Thx Powell done that can see how the HW is switched on but not the CH ! is it via the 3port valve ? will the pump work if i use the term block neutral ? or has it got to go back to the boiler ? thats going to be a nightmare .
thx Mark.

 

[markspark]

Found this ....
Quote

'For HW the valve is not energised, nor does it take part in heating of water. The pump and boiler are brought on line by the cylinder thermostat.

If CH demand is made while HW is being heated, white wire has 240v applied to it which make the valve travel to mid position.

Once water has heated and reached set temperature, Grey wire is energised (for full travel of valve), so that radiators only heat.

If valve not motoring to midposition, look for wiring defect on white wire (should be live when calling for heat). Using the neon tester will be futile- use a multimeter.

To recap.

HW only- valve does not move.
HW and CH. Valve midposition. Boiler & pump energised through cylinder stat
HW up to temperature and CH calling. Valve motors rest of the way via grey wire.
HW channel off and CH channel on and calling. Same as above but in this case grey powered from off contact of programmer and not cylinderstat.'

this explains the first bit of my Q but not the second bit 'will it be ok to put pump on term block neutral ' ?
regards Mark.

 

[doitall]

Very good but not 100% accurate.

The grey wire is the cylinder stat satisfied.

The white wire is the call from the room stat.

The pump and boiler is powered from the orange wire.

 

[Boilerman2]

On the Suprima ORANGE goes to Boiler SwL, The PUMP MUST BE FED FROM THE PUMP TERMINAL AT THE BOILER for the pump run on to work

 

[markspark]

Thanks for the replys connected up ok and switched on and all working fine, switched heating\HW off and ................ the boiler kept running dunno why the only thing i can see thats different on my drawings is the room stat setup .Ive got CH clock 240v -4- on ep2002 connected to L on the room stat the n\o -sw L - (3) on the drayton RTS1 then goes to the Brown\white cable on the 3port valve.......... the problem is that if you look on the potterton suprima installation instructions pg 31 http://www.potterton.co.uk/docs/Potterton_Suprima_HE_Installation_and_Service_Instructions.pdf it shows the ch 240v connected to the *N\C* of the room stat (my room stat has a n\o !!) the common is then connected to the valve. For me its the wrong way around but hey what do i know do i need a new room stat ?

Regards Mark.