Vailant Extotec Pro 28 - pressure loss

[Scott6488]

Sounds like an expansion related issue. If it was the sensor, I’d expect the analogue gauge to remain at pressure.

Expansion vessel has been replaced, and so has the prv

 

[terryplumb]

Look for a plastic pipe below your boiler ,that's the condensate pipework.

 

[CBW]

Expansion vessel has been replaced, and so has the prv

I know that, but if you’re not putting much water in, sometimes a sign.

 

[Scott6488]

Look for a plastic pipe below your boiler ,that's the condensate pipework.

I believe the condensate pipe on these runs into a trap that just sticks out under the boiler. The water in there was full of "stuff" the first time I looked at it

. I've just emptied I and this is what I found

 

[terryplumb]

Show us a picture of Below the boiler ,this trap and pipework from it

 

[Scott6488]

 

[terryplumb]

The white plastic pipe on the right hand side is the condensate pipework. Follow it ,to a drain or a connection point to waste Pipework in the property,which could be under a sink,( amongst other possibilities)

 

[Scott6488]

The white plastic pipe on the right hand side is the condensate pipework. Follow it ,to a drain or a connection point to waste Pipework in the property,which could be under a sink,( amongst other possibilities)

It runs along the wall to the right and then drops down under the floor, I assume from there it joins a drain point somewhere

 

[terryplumb]

When boiler is operating ( central heating for instance) it produces condensate (slightly acidic water), which runs down that pipe to drain.
When boiler is idle it doesn't produce any. So ,if when idle, fluid is trickling down the condensate pipework the heat exchanger in your boiler is perforated / pin holed ,and the primary system water is escaping,hence the pressure drop.
So finding the end of the pipe ,would enable you to view it ,and confirm.

 

[Scott6488]

When boiler is operating ( central heating for instance) it produces condensate (slightly acidic water), which runs down that pipe to drain.
When boiler is idle it doesn't produce any. So ,if when idle, fluid is trickling down the condensate pipework the heat exchanger in your boiler is perforated / pin holed ,and the primary system water is escaping,hence the pressure drop.
So finding the end of the pipe ,would enable you to view it ,and confirm.

As it dissapears under the floor to a point I can't see, the I guess my only option would be to put a break in the plastic pipe after it's left the boiler to see if anything is coming out. At least that would be easiest to have rejoined

 

[terryplumb]

As it's technically part of the flue ,you really shouldn't .

 

[Scott6488]

I've pulled the condenser drain pipe away from the underside of the boiler. There is a constant drip coming from there just now but the boiler is running.

 

[Harry Bloomfield]

Sorry not sure what you mean by the condensate pipework. I have a bag over the outlet from the prv and there's nothing coming out of there

Coming out the back of the boiler is a pipe which leads to a drain, usually an outside drain, probably a plastic pipe. As moisture condenses inside the boiler, in a condensing boiler, the moisture/water has to be drained.

Terry's idea is to check that drain and see if any rusty looking water might be coming out of it, which will help confirm the boiler is actually leaking when it gets hot.

 

[Scott6488]

Coming out the back of the boiler is a pipe which leads to a drain, usually an outside drain, probably a plastic pipe. As moisture condenses inside the boiler, in a condensing boiler, the moisture/water has to be drained.

Its constantly dripping when the boiler is running

Terry's idea is to check that drain and see if any rusty looking water might be coming out of it, which will help confirm the boiler is actually leaking when it gets hot.