Boiler losing pressure twice a day HELP!!!

[maverick718]

Hi guys, I'm new to the forum so heres a quick hello.

Right........onto the problem. I have a Ideal Icos HE24 system boiler that is losing pressure around two times a day. Ifirst noticed something wrong at the weekend when my boiler was showing the F L error code which relates to the flame ignitor electrode I think. Since then, the boiler has been losing pressure. I have checked the s valve for the condensate and that is fine. There are no obvious leaks in pipework and radiators, valves etc... The F L error has only ever happened first thing on the morning and once I get the boiler going by doing a reset, it seems to work fine. Unless it is something to do with the pressure being cool on a morning , I don't know as i'm not a plumber. What i will say is that when the boiler is running, the pressure does rise from 1.5 to around 3.0 bar. When it is turned off, it seems to lose pressure within aroun 2-3 hours back to near zero.

I then called out my friend who is a British Gas engineer (who is only qualified as a gas fitter but not water) and he took the cover off and checked the air in the expansion vessel. When he pressed the valve in, no air came out so he thought the problem was in that area. He then proceeded to get his foot pump out to try and pump it up only to find out that for some reason, it was blocking him from pumping up. he told me that basically the vessel is kaput. he then said that a cheap way of a repair is to fit an external expansion unit in the airing cupboard where the hot water tank is but he couldn't find a central heating pipe due to his lack of knowledge on the water side and advised me to call a plumbing fitter.

If anyone can confirm that this could be the problem that my friend has described or may come up up with any other ideas on what the fault maybe then that would be great as i have a limited amount of knowledge of plumbing and wont touch gas or water.

Thanks in advance

 

[Blake]

EV sounds about right from what you have described.

 

[maverick718]

why would the Expansion Vessel stop him from pumping air in when there is supposably, no air in?

might be a silly question but I would like to know.

 

[Blake]

The EV has a diaphragm in it, air on one side and water on the other which allows for the expansion of the heating system. If the diaphragm is damaged/broke then this will make it difficult to pump air in and will cause the issues you have described.

 

[markproperjob]

hi.
I work as subbie diagnostics engineer for a company repairing boilers fitted under warmfront grants in the south west.
most boilers fitted under this grant are icos he24's or 35's, or valiant ecotecs.
ive lost count of the times ive attended jobs showing your symptoms, and the (very) common faults found on icos are ruptured heat exchangers, where system water leaks internally and evapourates quickly, causing regular pressure loss with no obvious cause, or the pipe valves below the boiler are not tight enough, again causing pressure loss but not always with a puddle of water, as slight weeps can evapouate on hot pipes before being seen.
hav not got a clue why your chap couldnt fit a pump to the vessel, if you can press the shraeder valve pin in and hear no air, this does indicate a de pressurised vessel, but if the vessel is knackered, you will always get water through this valve if its ruptured.
try this...
when your pressure is showing zero and system cold, connect another foot pump to the vessel shraeder valve, as i cant see why the first pump couldnt pump air into vessel unless the pump was at fault, and try pumping air into the vessel until it reads one bar on the boiler guage. if the guage needle bounces significantly, then the vessel is dodgy and needs renewal or a larger externaL vessel can be fitted.
boiler manufacturers reccomend fitting extra vessel in system anyway. then you can just leave faulty vessel in situ.
and as a test, tie a small freezer bag over the pressure relief valve poking outside your wall. if the expansion vessel is indeed faulty, then it will allow over expansion of the system, the pressure relief valve will open and dump water ino your freezer bag. you can also use this method, but leave boiler off all day after re pressurising it, if you have water in the bag with a cold and therefore not over expanded boiler, then you just have a leaky pressure relief valve. easy fix.
hope of help.

 

[GrahamM]

To be honest any qualified gas engineer should know how to pressurise an expansion vessel. It really is not complicated and is an integral part of the system.
Get yourself an experienced engineer to check your expansion vessel. It has either lost pressure or is ruptured.

 

[mikeymike]

hi my ideal isar he 24 is leaking from the overflow pipe..which is resulting in low pressure haveing to fill up every day..even when ch is not in use please help??
thanks

 

[maverick718]

Just to fill in, my problem was fixed back in feb. Indeed the expansion vessel was kaput and I also had to change the pcb as it was faulty therefore givin the FL error all the time. Boilers been fine touch wood since then without a problem.

Your problem seems pretty similar to mine in a way mike. Expansion Vessel.

 

[mikeymike]

i know it may seem a daft question but where is the expansion vessel located and whats its job?
thanks

 

[broggo]

The expansion vessel is located inside the boiler, its job is to take up any water expansion as it heats.