Open-vented system, valve positions...

[ddavex]

Hi,

The pump in my CHS packed-up recently and the valves either side of it weren't working properly either so ended up having to drain the whole system. But prior to that, when I initially started to remove the pump water came gushing out and I grabbed any valve I could find and turned them off with no effect. All well and good now, sort of! I put them back to where I thought they were before but I've noticed the boiler [Potterton Pr1maF] is now having problems starting-up. I hear the fan starting and a gurgle of water, but then it winds down, does this every ten seconds or so, maybe up to ten times then it will suddenly jump into life. I'm guessing it might not be getting enough water but I'm not sure. Can someone tell me what position the two red tap valves should be in on the photo below (one's obscured slightly by the motorised three-way valve), or is it something else that is borked? Thanks in advance.

Dave.

 

[Paul Barker]

The visible one is just to balance the cylinder see balancing in sticky.

The one out of sight is a bipass, could have it half to 3/4 shut.

The shaft of these gate valves can break but the wheel turns. That may have happened with the hot water one in a closed position.

Ball style Pump valves are useless as you experienced. They never work when you need them later on, best to use gate valve style, but those can break at the shaft when later required to function. Basically it's often necessary to get a little wet, and pump nuts are always getting hacksawed through to boot.

 

[Paul Barker]

There is an air seperator fitted which is a nice touch, and I see they are gate pump valves, so make sure they are not stuck mostly shut i.e. broken shaft scenario, might have to drain down remove them fit new ones to existing compression nut and olive in each case, simple job.

 

[wilhelm]

errrrrrrr.............

can you translate that into plumbage?


non the less...quite amusing.

 

[ddavex]

Thanks Paul, bypass valve turned to about 3/5's shut, the boiler seems to be behaving a bit better now, will keep an eye on it. This other valve, I've checked the couple of sticky posts on cylinder balancing with little luck, is it the same as balancing the radiators, ie. the out pipe should be 20c cooler than the in pipe?

The visible one is just to balance the cylinder see balancing in sticky.

The one out of sight is a bipass, could have it half to 3/4 shut.

The shaft of these gate valves can break but the wheel turns. That may have happened with the hot water one in a closed position.

Ball style Pump valves are useless as you experienced. They never work when you need them later on, best to use gate valve style, but those can break at the shaft when later required to function. Basically it's often necessary to get a little wet, and pump nuts are always getting hacksawed through to boot.

 

[Paul Barker]

20c for a condensing boiler.

Wilhelm, what don't you understand?

 

[wilhelm]

apologies paul.....err i dont think i understand......

....plumbing

usual scenario...... read post.....get confused...reply.

make complete kerlown of myself...... and..
life goes on..

sorry mate.

 

[Paul Barker]

Ah well you see I started life after schools as an Economist, then thought I might make a good Accountant, but soon realised I was cut out for photography, which failed during the late 80's so had to go despatch riding, precipitating a near death experience which led me to realise all I was cut out for in life was to be a nurse, when I got my nervous breakdown from nursing it occured to me that all along I had been good with my hands so here I am a posh plumber and proud of it. My hobby of 1930's era electronic engineering and my radio amateur license has come in handy too.

So I might not sound like a plumber. At first the "real plumbers" in the merchants used to snigger at me, but anyone who's decent around here is now a mate and the sniggerers are going round puting non condensing Europas and the like for old ladies and making a killing.