Hi, I have a Vaillant ecoTEC plus 831. Having drained and removed a rad whilst redecorating my dining room I need to repressurise/ top up the system. This is something I've done before with no hassles using the two grey valves under the boiler. Turn from closed to open, watch the guage go up, turn off again.. simple... However, on this occasion I've opened both valves to a resounding silence. I tried removing the boiler side end of the feed inlet hose and opening the supply side and water flows fine so it's not like there's a random tap in the supply that's been turned off. I guess the second valve could be at fault although I've turned it with the plastic head removed and it 'feels' fine. Still nothing. Are there any other things I can try before I get an expensive gassafe guy in to rummage? I'm fine with plumbing, but the law prohibits etc.. sigh. Any ideas would be appreciated. GB
odd ,can you post pics ? what happens when you open the valve at boiler end ,with no hose attached ?you may have a non return valve that is seized up and closed.
Thanks KIAB but I know the system volume is down from draining the large radiator. Even if it was just the guage I'd expect some movement of water through the filler hose at this point.
Odd indeed. This is looking up under the boiler. Supply cones in to the right hand grey valve, through Flexi then into the system via the left hand grey valve. There are, I think, flat head circuit valves but they have no impact. As you can see the double check valve is on the inlet end and I've had water flowing past that with the small (left) end of the hose detached.
left hand valve .remove hose then turn valve on to see if water comes out ( have cloth or towel handy) .if no water comes out your problem is there.
JP he has not tried with the hose disconnected . only a physical obstruction would prevent mains pressure water from entering into the primary system pipework.
good idea Kiab ,easier than my suggestion ,but will give the same result I.e. is left valve obstructed .
JP ,of you re read that paragraph ,he is telling us the hose was disconnected and he opened the supply side ( which is the right hand valve on the mains branch ) and water flowed out . the problem is the left hand valve .
kiab if right valve was faulty he would not get water flowing out of it thru the hose , as he said he gets.
the right valve is on the mains cold water feed to the boiler and there is a double check valve in line. can't follow your logic Kiab ???
Has the actual boiler pressure been mentioned ? A reading from the round mechanical gauge and a reading from the digital display as mentioned the round gauge could be giving an incorrect reading.
The is were coming in, through the mains supply Valve and out of the hose which I disconnected. I will note go and try this the other way around but as the boiler is at the top of the system and there is a shortage of water in it I may not get much. The pressure guage is on zero. Digital sensor suggests 0.4 bar. Thanks for all the help so far. I'm a bit mystified. BRB.
Ok so this is the boiler side valve... The small hose end is the supply from mains. I have disconnected that and opened this valve... Nothing.. So then I used the little tapless square head valve on the side and water comes out of the associated hole so would you agree it sounds like the grey tap valve has probably failed? The knarley central valve I presume is to isolate the actual heating water circuit. It makes no difference to inlet anyway.