Keston Boiler - long term leak

[anotherplumber]

I have Keston Boiler which has been leaking for several months. The pressure decreases quickly more than one bar in one day as the boiler is used. Several plumbers have had a look at it and do not seem to solve the problem.

How often does the air from radiator need to be bled? A lot of air is getting into the system thus radiators not heating up.

Should I find a leak detector -any recommendation on what the next plan of action should be? based in London.

 

[Puddle]

Although Keston are not great boilers,this problem is probably not the boiler if you have had checked a few times,they would of checked the p/r valve on boiler and condensate but a leak somewhere else on the system
It must be on the ground floor as if above you would have seen leak damaging fabric by now

Time to get some floor boards lifted maybe


imhoo

 

[anotherplumber]

Yes I agree - I'll do so - what is the general opinions on thermal imaging leak detection

 

[GQuigley67]

expensive, have you got some crawl space under the floor ?

 

[anotherplumber]

Maybe 8-10 inches. The boiler is on the ground floor - garage so leak must be downstairs. But short of ripping the whole of the downstairs open I have no clue where this leak is - there no obvious signs or maybe I don't know what to look for?

 

[GQuigley67]

well in that case then i would probably suggest thermal imaging, don't know cost wise how much it is as i have never had to do it yet.

 

[Simon F]

The pressure decreases quickly more than one bar in one day as the boiler is used.
How often does the air from radiator need to be bled? A lot of air is getting into the system thus radiators not heating up.

does it only loose pressure when the boiler is on ?
as you will be regularly topping the pressure up, you are introducing new water that has air in it.

 

[GQuigley67]

it will decrease quicker because the pump is circulating the water and the increased pressure from the heated water, if you have ruled out expansion problems then it will be a leak

 

[yo1]

you could close the isolation valves on the boiler and leve it for a day then check the pressure to be sure its not the boiler..

 

[anotherplumber]

yes that's right only when the boiler is on. And yes we top up the pressure every night when the heating goes off.


you're right I probably am introducing new water but failing to top the pressure will mean Brrrrrr cold house!!

 

[Simon F]

it will decrease quicker because the pump is circulating the water and the increased pressure from the heated water, if you have ruled out expansion problems then it will be a leak

its true it will decrease quicker but if there is a leak you would still expect some loss from a pressurised system when its cold. it is loosing 1 bar a day, a significant drop ! what pressure does it read when the system is hot
monitor the pressure over night pump it up, then check it before the heating comes on to see if there's a drop.
the reason I am thinking this is because although you say its been looked at, what was done do you know? did the plumber that came round look at the expansion vessel ?

 

[GQuigley67]

if there have been a few plumbers then surely at least one of them have checked the EV, i have had leaks which have emptied a system in a few hours, I now find that a bar a day is not alot lol

 

[reeb]

Have you checked the condensate when the boiler is off and you top the pressure up. If there is water coming out of the condensate when the boiler is off then it is likely to be a leak in the heat exchanger. I have had this problem with a keston C40 and apparently heat exchanger corrosion is a common problem with keston boilers.

 

[maks_rt_011]

Hi , feel sorry for u , Get new boiler instead , don't waste money on any repairing. This is the worst boiler ever. It works ok for first couple years and the turn to nightmare.

 

[Mbear]

Have u tried cutting condens pipe to prove its not the main h/e
We had this on a Keston about 3 months ago

 

[ralphg]

Sounds to me like the expansion vessel needs attention. Is there water coming from the safety relief valve? Thermal imaging will work well on a solid floor but not much use if there is a void and floorboards

 

[thereisawizza]

Agree with all on the heat exchanger, had 2 x 130's over the past 6 years, both leaking from coil in heat ex. New boiler time!

Just in cae you do think about getting the heat ex changed, we had a cust who had h/ex replaced 2 x years ago by others because of leak, new h/ex has now burnt it's inner insulation out (tripping thermal fuse) and appliance is being replaced......