Boiler loosing pressure

Kristoffs

Hi Everyone,

Im hoping that some knowledgeable person can help me. 

I have an Ideal Logic System 24 boiler which is loosing pressure and is 5 years old. It started off needing topping up once a week and now it is down to needing topping up daily. I had an engineer round who did very little (stuck a screwdriver into the Schroeder valve to make sure it had air and not water) and then told me I have a leak on a radiator. 

I have checked all the radiators and found no signs of a leak so if there is a leak it would be in the floor or ceiling but no damp patches are showing (been loosing pressure for a few months now). 

Before I start taking up floors I want to make sure the boiler is ruled out and from reading the forums I have been checking various parts of the boiler. 

Firstly I have checked that no water is escaping from the pressure release valve, which it isn’t. 

Secondly I de-pressurised the boiler and checked the pressure on the expansion vessel which was at about 0.2bar so topped it up to 0.75 bar as per the manual. Now the pressure gauge moved from 1 bar to around 2 bar when heating where as for the last 5 years it has only gone to about 1.4 bar. 

Thirdly I have pressurised the boiler to 2 bar pressure closed off the flow and return valves and left overnight and in the morning the pressure was down to 0.8 bar. When opening the valves the pressure gauge moved slightly but no real drop. 

I have also noticed that the condensate trap fills every 3-4 minutes. Is this normal?

I plan to have ideal come out to fix the boiler but I want to make sure that it is the boiler before paying £300 for them to come out and tell me it is a leak in my central heating. Is there a test I can do to make sure it is the boiler and not that the flow or return valve is letting by when closed in my over night test. 

Any suggestions will be greatly appreciated. 

Regards,

Kris

Amba_Gambla

The same is happening to me (pressure gone, refilling boiler and firing up, pressure goes sky high, then needs refilling a few days later) - I know very little about plumbing/boilers, but have spoken to two plumbers over the phone (not able to have had one out yet) they have both suggested that my expansion vessel has gone and will need replacing.

Jeepers_Creepers

Amba_Gambla said:

The same is happening to me (pressure gone, refilling boiler and firing up, pressure goes sky high, then needs refilling a few days later) - I know very little about plumbing/boilers, but have spoken to two plumbers over the phone (not able to have had one out yet) they have both suggested that my expansion vessel has gone and will need replacing.

The 'soaring pressure when system heats up, followed by a loss of pressure when off' is classic Expansion Vessel issue. Whether it's actually faulty and needs replacing or whether it's simply a matter of recharging it you won't know until the guy comes out to check. If you are up to it, if you can ID the Schrader valve and press it briefly to see what happens - air or water comes out - then that's one 'layman' test. Tho' not for every layman.

Jeepers_Creepers

Hi Kris.

Thanks for the detailed post! You clearly have a good understand of what's going on.

I have an Ideal Logic System 24 boiler which is loosing pressure and is 5 years old. COOL. THAT'S YOUNG. ANY CHANCE IT'S STILL UNDER WARRANTY? It started off needing topping up once a week and now it is down to needing topping up daily. I had an engineer round who did very little (stuck a screwdriver into the Schroeder valve to make sure it had air and not water) and then told me I have a leak on a radiator. AS YOU SAY, HE DID VERY LITTLE; YOU'VE DONE A LOT MORE.

I have checked all the radiators and found no signs of a leak so if there is a leak it would be in the floor or ceiling but no damp patches are showing (been loosing pressure for a few months now). 

Before I start taking up floors I want to make sure the boiler is ruled out and from reading the forums I have been checking various parts of the boiler. ABSOLUTELY - YOU WANT TO CHECK WHETHER IT'S THE BOILER BEFORE WRECKING YOUR HOUSE!

Firstly I have checked that no water is escaping from the pressure release valve, which it isn’t. YOU DID THIS HOW? PRESUMABLY BY CHECKING NO WATER COMING FROM THE 15MM COPPER DISCHARGE PIPE?

Secondly I de-pressurised the boiler and checked the pressure on the expansion vessel which was at about 0.2bar so topped it up to 0.75 bar as per the manual. Now the pressure gauge moved from 1 bar to around 2 bar when heating where as for the last 5 years it has only gone to about 1.4 bar. THAT'S WEIRD, AND I CANNOT EXPLAIN IT. AS YOU TOPPED UP THE 'AIR' SIDE, DID YOU LEAVE A BLEED SCREW OPEN TO ALLOW WATER TO BE EJECTED FROM THE WATER SIDE WITH EACH 'PUMP'?!

Thirdly I have pressurised the boiler to 2 bar pressure closed off the flow and return valves and left overnight and in the morning the pressure was down to 0.8 bar. When opening the valves the pressure gauge moved slightly but no real drop. 

I have also noticed that the condensate trap fills every 3-4 minutes. Is this normal? COOL - THAT'S A GREAT TEST! IF YOU ISOLATE THE FLOW AND RETURN PIPES, THAT IS THE BEST WAY TO SEPARATE AND CHECK WHETHER THE LOSS IS WITHIN THE BOILER OR IN THE PIPE/RAD SYSTEM. IT SEEMS PRETTY CONCLUSIVE FROM YOUR TEST THAT IT AIN'T THE RADS AND PIPEWORK. WHEN YOU SAY THE CONDENSATE TRAP FILLS EVERY FEW MINUTES, DO YOU MEAN WITH THE BOILER OFF AND COLD, OR WHEN IT'S RUNNING? IF THE FORMER, THEN THAT'S A PRETTY GOOD INDICATION OF A LEAKING MAIN EXCHANGER - THERE SHOULD BE NO WATER COMING OUT THE CONDENSATE PIPE WHEN THE BOILER IS NOT IN USE.

I plan to have ideal come out to fix the boiler but I want to make sure that it is the boiler before paying £300 for them to come out and tell me it is a leak in my central heating. Is there a test I can do to make sure it is the boiler and not that the flow or return valve is letting by when closed in my over night test.

YOU HAVE CARRIED OUT ALL THE IMPORTANT TESTS. ALL YOU NEED TO ENSURE IS THAT THEY'VE BEEN CARRIED OUT PROPERLY. IF YOU PRESSURISED YOUR SYSTEM TO 2 BAR AND THEN ISOLATED THE RADS AND PIPEWORK BY FULLY SHUTTING OFF THE BOILER'S ISOLATING VALVES, THE RESULTS ARE PRETTY CONCLUSIVE.

WITH THIS TEST, IT'S EITHER (A) THE PRESSURE STILL CONTINUES TO DROP, INDICATING A LEAK FROM WITHIN THE BOILER, OR (B) THE PRESSURE REMAINS STABLE, BUT RE-OPENING THE ISOLATING VALVES GIVES AN IMMEDIATE DROP, INDICATING A LEAK IN THE RADS AND PIPEWORK. FOR THE FORMER SCENARIO, WHEN YOU REOPEN THE ISOLATING VALVES, YOU MAY EVEN SEE A SMALL UPWARDS PULSE IN PRESSURE, SINCE THE RADS WILL HAVE BEEN SITTING AT 2BAR WHILST THE BOILER 'EMPTIED'.

Almost every modern boiler will come with at least 5 years warranty on its main exchanger. Even if the 5 years are up, it still shouldn't fail; almost certainly you can launch a claim against the supplier/manufacturer. It's good that you are having Ideal themselves coming out to look at it and not a third party - it'll be easier to make that claim. There's also a good chance that, if it is the main EX, they'll offer to do so.

Kristoffs

Thank you for your response Jeepers. 

Unfortunately it seems to only have a 2 year warranty on the boiler. 

A bag over the PRV 15mm copper pipe showed no leak. 

When topping up the EV, I bled the pressure on the boiler till the pressure was 0 then put a few pumps in and bled the pressure again on the boiler till 0. I continued to do this until the boiler gauge stayed at 0 when pumping. 

The trap fills every 3-4 minutes when heating. I have currently taken the trap off and put a bowl under while I’m out to see if any water is leaking while cold. 

Jeepers_Creepers

Kristoffs said:

Thank you for your response Jeepers. 

Unfortunately it seems to only have a 2 year warranty on the boiler. 

A bag over the PRV 15mm copper pipe showed no leak. 

When topping up the EV, I bled the pressure on the boiler till the pressure was 0 then put a few pumps in and bled the pressure again on the boiler till 0. I continued to do this until the boiler gauge stayed at 0 when pumping. 

The trap fills every 3-4 minutes when heating. I have currently taken the trap off and put a bowl under while I’m out to see if any water is leaking while cold. 

2-year ma botty. The main exchanger is one of the most expensive components in there - possibly the most - and is usually enough to condemn a boiler to the scrapheap if it fails.

And early condensing boilers did, in large numbers. Why? Because they used stupid materials like aluminium and cast iron for the part that was both heated and soaked in dilute acid. Jeepers.

Hence many boiler manufacturers subsequently giving good solid warranties when they changed to Stainless Steel. Quite common for a new warranty to be something like "3 years on all parts, and 10 for the main exchanger..."

Anyhoo, is it the main EX? Not conclusive from what you say - the condensate trap will fill quite regularly when the boiler is in use. It's sometimes hard to determine whether it's 'condensate' or 'system water', because the leak issue is often exacerbated when it's running hot - the cracks expand, so it leaks alongside the normal condensate emission.

I'm a bit concerned about your 'removal of the trap', tho' - you do know that this 'traps' the exhaust gases, and leaving it off could lead to a quite bad case of death? Usually I would suggest loosely rubber-banding a clear bag over the end of the condensate pipe whilst the boiler is not in use.

BUT, you clearly have a good handle on what you are doing, so will obviously replace the trap correctly before firing up the boiler.

Yes?! :-) 

Kristoffs

I will not be running the boiler without the trap connected back up properly. The trap empties into the same waste that the water softener empties so it would be hard to determine exactly where any fluids caught originated from. 

Now I am home I can see that the boiler lost most of its pressure when cold and although liquid was in the bowl this could have come from moisture left in the flue so I have emptied the bowl and repressurised to see if any more water escapes. 

davilown

Kristoffs said:

Hi Everyone,

Im hoping that some knowledgeable person can help me. 

I have an Ideal Logic System 24 boiler which is loosing pressure and is 5 years old. It started off needing topping up once a week and now it is down to needing topping up daily. I had an engineer round who did very little (stuck a screwdriver into the Schroeder valve to make sure it had air and not water) and then told me I have a leak on a radiator. 

I have checked all the radiators and found no signs of a leak so if there is a leak it would be in the floor or ceiling but no damp patches are showing (been loosing pressure for a few months now). 

Before I start taking up floors I want to make sure the boiler is ruled out and from reading the forums I have been checking various parts of the boiler. 

Firstly I have checked that no water is escaping from the pressure release valve, which it isn’t. 

Secondly I de-pressurised the boiler and checked the pressure on the expansion vessel which was at about 0.2bar so topped it up to 0.75 bar as per the manual. Now the pressure gauge moved from 1 bar to around 2 bar when heating where as for the last 5 years it has only gone to about 1.4 bar. 

Thirdly I have pressurised the boiler to 2 bar pressure closed off the flow and return valves and left overnight and in the morning the pressure was down to 0.8 bar. When opening the valves the pressure gauge moved slightly but no real drop. 

I have also noticed that the condensate trap fills every 3-4 minutes. Is this normal?

I plan to have ideal come out to fix the boiler but I want to make sure that it is the boiler before paying £300 for them to come out and tell me it is a leak in my central heating. Is there a test I can do to make sure it is the boiler and not that the flow or return valve is letting by when closed in my over night test. 

Any suggestions will be greatly appreciated. 

Regards,

Kris

If you've isolated the boiler (where you've shut off the radiator system) and the pressure is still going down, it's likely to be a leak from the heat exchanger. TURN THE BOILER OFF FIRST You can do this by turning off the 2 valves not involved in the refill loop (those valves that allow you to top the pressure back up). Leave it over night and if it drops, it's definitely the boiler.  Just to confirm, put a container under the condensate pipe - if it collects water then its the boiler.

My plumber said this wasn't very common and didn't check it so I did - funnily enough the engineer from Ideal agreed with me and replaced it free of charge under warranty just last week.

Jeepers_Creepers

How old is your boiler, davilown?

Jeepers_Creepers

Yes, it's looking likely here too, davilown.

Water can only be lost from an isolated boiler in three ways: the boiler just leaks (it'll be all over the floor), the PRV lets by and water escapes out the discharge pipe (not in this case) or it leaks via the condensate pipe - which almost certainly means a cracked main EX.

Kris, get ready to insist on a free repair. I suspect you won't have to try too hard - I have heard on here that Ideal is quite an honourable company.

Kristoffs

Thank you guys. 

Ideal are coming out on Thursday so I guess I’ll find out soon.