cylinder stat voltages

Just testing the voltages and i'm getting 240v on the common wire when programmer calls for heat, but getting 180v on 1 and 240v on 2?

when I turn the stat down I get 40v on 2 (backfeed from valve?) and 240v on 1?

Is this normal or a duff stat? would of thought it would just switch from 40v to 240v when turning stat up and down?

cheers.

Do you have problem with your system?

As you are testing the stat with the wiring in place, you should expect some back feeding voltage this is normal especially with Y plan and similar systems - the only way to test a stat properly is to completely disconnect it and test using OHMS scale on a multimeter reading should be infinate when contact open and as near to Zero Ohms when contact closed

back feeding on cylinder stats is not that uncommon, on some systems it can cause issues but if you arn't suffering any then dont wory.

the system is working fine, but noticed when the central heating has been on and off, the 3 port valve holds the last position and the valve head becomes very hot even when the pipes have cooled down, also when you operate the manual lever it does not spring back, the valve just holds the position and then head heats up!

I dont know if this is normal so started testing voltages.

I tested the stat with 1 and 2 disconnected from the wiring center, just the common conncted with programmer calling for hw, so had 240v on the common but the 1 and 2 had 180v and 240v, then when i switched the thermostat i had 240v and 40v

I tested the stat as i was getting 180v on the grey wire when there should of been 0v or 40v feedback. The programmer is working fine have tested that.

Just dont think the valve head is supposed to get hot and vibrate slightly when holding its last position?

Thanks!

neilht said:

the system is working fine, but noticed when the central heating has been on and off, the 3 port valve holds the last position and the valve head becomes very hot even when the pipes have cooled down, also when you operate the manual lever it does not spring back, the valve just holds the position and then head heats up!

Click to expand...

Perfectly normal the valve is being held in last position by 230v on the grey wire from either hw off/satisfied.
It's 230v on the grey that enables the valve to go to ch position only.
otherwise it would only go to mid position.

The only way that the valve motor won't get warm is if hw was last port of call then the valve is in it's relaxed position.