expansion vessels

[obseen16]

Hey guys,

Just wondered which one you come across more often: an expansion vessel which has lost its charge OR one which has a split diaphragm and requires replacing OR the ones which get a blockage in the flexi (hate these ones)

its weird i havent had an expansion vessel problem for months then all of a sudden last week i re- charged 3 and replaced 1

but do you guys replace more or re-charge more on average?

 

[dancinplumba]

replace

 

[Barry98]

recharge once then replace

 

[Gordon T]

Replace.

 

[gasmarc]

Recharge first and if it leaks I replace it ,On some boilers you have to remove it from the wall which can be a nightmare or put one in externally if possible

 

[dontknowitall]

Recharge. Make notes of what size, etc, then replace on next visit (having bought it first).

 

[heliotrope]

I reckon I pump up more than I have to replace.

I have never come accross a blocked flexi on a vessel but had some damaged ones
on Grant oil boilers and one on a WB Hi Flow.

 

[SimonG]

With oil it's mainly recharge (at service) but find that the main issue is undersizing. Nobody seems to give consideration on installation for the size of the vessel that comes with the boiler. Tend to find most issues with undersized vessels. Have had 1 blocked flexi.

 

[boblydon]

pressurise, at least 95% of sealed systems i attend need this doing, even if they have been serviced (well according to the customer) every year.........why is it that the majority of heating engineers never check/recharge the vessels during service?????, most of the heating engineers i speak to in the suppliers don't even own a foot pump to carry out a recharge....i have a small compressor which works great.

Some of the donkeys don't even realise you have to isolate and drain the boiler to do it !!!!!!

 

[keltoyboy]

pressurise, at least 95% of sealed systems i attend need this doing, even if they have been serviced (well according to the customer) every year.........why is it that the majority of heating engineers never check/recharge the vessels during service?????, most of the heating engineers i speak to in the suppliers don't even own a foot pump to carry out a recharge....i have a small compressor which works great.

Some of the donkeys don't even realise you have to isolate and drain the boiler to do it !!!!!!

Why do you need to isolate the boiler.....normally just drop pressure below charge pressure, and check/charge then??

 

[kirkgas]

Why do you need to isolate the boiler.....normally just drop pressure below charge pressure, and check/charge then??

if the boiler is downstairs in a 2 storey house it is quicker to shut iso's and drain boiler than to part drain with iso's open just for water to drop from floor above back into boiler, if boiler is higher than rads then no need to shut iso's

 

[johnnyplumb]

if the boiler is downstairs in a 2 storey house it is quicker to shut iso's and drain boiler than to part drain with iso's open just for water to drop from floor above back into boiler, if boiler is higher than rads then no need to shut iso's

i never touch boiler iso valves , once bitten twice shy, it can be a problem getting replacement valves when they leak.

 

[tamz]

You don't need to drain it if you use a compressor but you will have to drop the pressure as it will rise as the water pushes out the vessel.

 

[gasmarc]

I tend not to touch isolation valves if at all possible as they tend to leak and you now have a system that leaks and something I never do is drain by the PRV unless replacing

 

[GrahamM]

I re-pressurise more than replace. Get the odd faulty schrader, but more often than not the vessel has just lost pressure after a few years, just like a car tyre.

 

[desrob]

I re-pressurise more than replace. Get the odd faulty schrader, but more often than not the vessel has just lost pressure after a few years, just like a car tyre.

what did you do with faulty schrader how did one change it, in situ or remove and did you just r

 

[GrahamM]

what did you do with faulty schrader how did one change it, in situ or remove and did you just r

Last one I did was only last week. Was an old Alpha CB28 IIRC. Was bit awkward. Boiler was at back of dark cupboard with flue almost hard against ceiling. Pressure had been rising and blowing off for some time. First off I depressed the schrader which continued to pass air so was valve was gubbed. I removed schrader with removal tool and topped up system pressure to 1 bar. No water from valve usually indicates ex. vessel is sound.
New schrader was very awkwardly put in with aid of mirror. This was hard part due to awkward boiler position and limited access to rear of boiler. System was then drained and vessel pressurised to 1 bar approx.
System re-filled and ran on max for some time. Pressure sitting stable with no sign of PRV passing.
Jobs a guid yin!

Some LDF on schrader can sometimes indicate valve faulty.

 

[keltoyboy]

last one i did was only last week. Was an old alpha cb28 iirc. Was bit awkward. Boiler was at back of dark cupboard with flue almost hard against ceiling. Pressure had been rising and blowing off for some time. First off i depressed the schrader which continued to pass air so was valve was gubbed. I removed schrader with removal tool and topped up system pressure to 1 bar. No water from valve usually indicates ex. Vessel is sound.
New schrader was very awkwardly put in with aid of mirror. This was hard part due to awkward boiler position and limited access to rear of boiler. System was then drained and vessel pressurised to 1 bar approx.
System re-filled and ran on max for some time. Pressure sitting stable with no sign of prv passing.
Jobs a guid yin!

Some ldf on schrader can sometimes indicate valve faulty.

ldf ???

 

[Puddle]

ldf ???

Leak detection fluid

 

[keltoyboy]

Leak detection fluid

sorry guys....having a blonde moment....... flipping vino!!! :santa_cheesy: anyone got any handy gauges for checking the akward expansion vessels.....just ordered one from amazon with a long angled flexi on it.....

 

[gasmarc]

I still have a car one with a gauge and I havnt had one that i could not do except the odd ideal . Regin do one which is a stippru pump with a long hose

 

[negas]

i service 5 plus boilers per day worcester bosch and vaillants mainly and all the vaillants need pressurizing every year (ecotec) and now states it in the service instructions .The regin stirup pumps are very good with awkward to reach vessels and give a very clear reading

 

[gasmarc]

well if a boiler vessel needs recharging every year there is a fault on it , I never check the vessel unless there is a problem