Keston C35, pressure drop, no leaks

[Ted808]

Hi another head scratcher.....
Fella has a relatively new boiler- 3yrs old and the system pressure was being lost and he topped it up. Frequency increased to 2xday and then he called me... Been there, basement installation hence the keston twin flue, condensate is pumped, prv into a saniflo. Checked all the visible pipework, small system 3 rads and a towel rail. Checked the expansion vessel. Checked PRV, now I have the F + R isolated and pressure up to 2.8Bar. Ideal/Keston Teci sugested this to rule out a split heat exchanger... Not quite sure where to go from here. If there is condense/ liquid in the bucket, how will I know it's not condense- surely if he uses the the hot water, then there'll be a bit of condensate. If he doesn't use the water and the heat exchanger remains cold then the 'hairline' crack won't open up and there won't be any sign of anything? Also, found gooey white stuff in the mag filter and the water stinks, like fish or something. The pipework is under the floor and not accessible, but I could isolate and pump up and monitor- how often do you get cracked main heat exchanger. Fella didn't register boiler for warrantee, apparently.

 

[Allgoode]

Just a Ideal Logic rebadged,

Basically charge system to about 2.5bar max because some of the PRV's may seep as you get close to the 3bar mark.

I usually run the boiler at max so the system is nice & hot, switch off all external controls & inputs & let boiler pump/fan do it's overrun business.

When it's finished, turn the boiler off & pop out the fuse so customer cannot use boiler.

Isolate boiler from central heating circuit using the valves on the unions.

Leave overnight & see what the boiler pressure is when you go around next. (I always take a couple of pics before & after for comparison).

When you re-open the central heating flow & return valves see if there is any drop/rise in pressure.

That's about the only way to find out if the main HEX is faulty. (£286 fixed price repair for last customer, but they had an Ideal logic 30 combi).

Will cost the customer more in parts if you do the work & the benefit of the fixed price repair is they have a van load of parts and can replace anything else which needs it.

Also don't forget to completely empty the condensate syphon, i wet vacuumed it as well as the sump connection to get as much moisture out of the HEX casting.

Like the random bits beside the magnaclean particle separator, nice flushed system, not.

Also the condensate trap & flexi pipe don't look to great, what was it like in the sump area where the silencer & removable plate is?

If boiler pressure is good & condensate syphon is dry when you go around to check next day then the HEX is good & when you open valves i would expect the system pressure to drop indicating a system leak & not a boiler leak.

Hope it helps,

Andy

 

[Harvest Fields]

Heat ex leaking into condense? Turn boiler off. Leave for 20 minutes. Disconnect condense pipe under boiler and watch for drips. Or as above. System leak.

 

[Ted808]

Also the condensate trap & flexi pipe don't look to great, what was it like in the sump area where the silencer & removable plate is?

I never opened the sump, but yea condensate had this smelly white goo in it!
MY test of 2.8 bar for a few (4)hours- pressure dropped to 2.6bar.
BUT boiler wasn't hot and I didn't think to stop him using it- so he ran a little hw, there was about half a pint of liquid in the bucket-
could've been condensate tho - think I will see if Keston can do a fixed fee repair... OR test the rad piework,if ok, then change boiler?!
Sometimes you have to be a magician hey?

 

[king of pipes]

Are you getting the full story here the white deposits could be leak sealer ? I agree with H here leaning towards a leaking heat exchanger get the system hot and up to 2bar isolate the boiler on its valves open up the condense sump and have a look there . Kop

 

[Ted808]

Called Keston/ Ideal to see if they do fixed fee repair, turns out they can pay a late registration fee and get it fixed under the G ! £125- about 6days shy of 3 years late!! Anyway they going there today, I've asked cust to update me!...so we'll see. YES the white goo did have a ring of leak sealer about it!