Keston pressure loss

[keston1]

Am I missing something?

Just so you know, I'm an ex corgi registered fitter (long retired from it) never a heating engineer. I installed this system many years ago and really apart from this problem it works well. It's a Keston System 30 system boiler.

Ok, the system is losing at least half bar overnight sometimes more. It's in a brick outhouse with frost protection, low loss header etc etc etc

Definitely not a PRV issue either in boiler or expansion vessel. No apparent leaks in pipework but part of ground floor loop is in screed and can't easily be accessed but this is only about 10% of the loop.

In this cold I can't isolate the ground floor zone or the boiler for pressure testing independently.

As far as I can work out the only 2 options are a leak in the part of loop in screed or leak within boiler allowing system water to pass into the condensate pipe.

Is there any dye that can be added to the system water so I can see if it comes out with condensate?

If there was a crack in the heat exchanger or elsewhere within the boiler, could system water pass into the condensate?

Thanks in advance

 

[kidgreen61]

Sounds like a split hex, can you remove condi trap for a while and observe? Continual dripping will confirm.

Then you'll have a good excuse to scrap the thing.

 

[keston1]

That's my thoughts too @kidgreen61 but not something I want at this time of year ‍

Any recommendation for a replacement that won't suffer the same fate?

I'm assuming there's nothing else out there with the same flue arrangements which was the main reason for using a Keston in the first place.

 

[muggles]

There are boilers out there which have a twin flue option, but whenever a new boiler is fitted a new flue must also be fitted so what's in place now isn't really relevant

 

[keston1]

There are boilers out there which have a twin flue option, but whenever a new boiler is fitted a new flue must also be fitted so what's in place now isn't really relevant

It's relevant to the location in this instant, nothing to do with reusing the existing 2" plastic