Alpha CD28C Losing Pressure - no leaks

[garya]

Hi All, Been through many different posts but not managed to resolve my problem.

After being topped up to 1 bar I need to refill after approximately 7-10 days.

Got an Alpha CD28C with the premierpack, no leaks at the rads, been under the wooden floors and no leaks in the pipework, no air in the system, all radiators working, some very small drips on the floor tiles under the bathroom radiator the odd time (not every day) but wouldn't have thought enough to cause the drop in pressure, no leaks from prv outside, water comes out of the other pipe when the heating is on but have been told that this is condensate and to be expected (as it's a condensing boiler). Have pressed the valve at the expansion vessel, no water just air comes out, so from what i have read this is working ok, when the heating is on pressure remains at approx 1.5-2 bar.

Not sure what else to try, am i able to isolate this boiler from the pipework to see if its the boiler itself or the system, at least this would allow me to narrow it down a bit more.

Water from the system is blueish, is this the inhibitor which would have been added 18 months ago when the new boiler was commissioned?

Thanks.

 

[Agile]

To drop one bar in a week you only need a few drips.

Fix the leak and then you should see it back to normal.

Tony

 

[45yearsagasman]

Just to add to Tonys reply,make sure that when testing for charge in exp vessel by pressing the schraeder valve you replace any lost charge.

 

[garya]

To drop one bar in a week you only need a few drips.

Fix the leak and then you should see it back to normal.

Tony

Thanks for the reply Tony,

I'm not questioning your expertise but if only a few drips (and i mean a handful over the course of a week) can cause this to drop of 1bar why is it that when i have to top it up it sounds like i have to put litres of water back into the system? I just find it hard to believe that a few drips over a week would cause such a drop?

Thanks

 

[maddog1964]

To drop one bar in a week you only need a few drips.

Fix the leak and then you should see it back to normal.

Tony

Thanks for the reply Tony,

I'm not questioning your expertise but if only a few drips (and i mean a handful over the course of a week) can cause this to drop of 1bar why is it that when i have to top it up it sounds like i have to put litres of water back into the system? I just find it hard to believe that a few drips over a week would cause such a drop?

Thanks

you may be right but fix the leak to find out
why have a leak at all
if leak is fixed then if pressure drops then you can try something else but you must fix leak first

 

[gas4you]

Outside chance a leaking HE and draining through the condensate pipe

 

[TicklyT]

Bear in mind that any small leaks will probably leak more when the system is hot and the pressure increases, and, as it's then leaking hot water, that water will quickly evaporate, leaving little evidence.

 

[garya]

Many thanks for the replies, appreciated.

OK so i've had no leaks from the bathroom radiator for a couple of days but the pressure is still dropping, assuming i have no leaks in the pipework or radiators is there anything which could be awry in the boiler which would cause a loss in pressure?

In response to gas4you's comment - interested to know what the expected level of condensdate should be coming out of the condensate pipe, should it be a drip or a steady trickle? I have a steady trickle coming out when the heating is on...

 

[gas4you]

If it's only trickling when heating is on then it sounds as though it's not that.

Isolate the boiler from the heating system and leave for as long as possible.

If pressure drops it is the boiler, if it doesn't it is the heating circuit somewhere.

 

[garya]

If it's only trickling when heating is on then it sounds as though it's not that.

Isolate the boiler from the heating system and leave for as long as possible.

If pressure drops it is the boiler, if it doesn't it is the heating circuit somewhere.

Dave, Any tips on how i do this? Cant see anything that looks like a valve i can turn off, any pointers appreciated.

Ta

 

[gas4you]

Follow the 22mm flow and return pipes up to the boiler. There will be isolating valves on the end of them connected to the boiler.

Turn these off after pressurising the system to about 2 bar.

One word of warning, these valves may leak afterwards and cost an arm and a leg to replace

 

[garya]

Follow the 22mm flow and return pipes up to the boiler. There will be isolating valves on the end of them connected to the boiler.

Turn these off after pressurising the system to about 2 bar.

One word of warning, these valves may leak afterwards and cost an arm and a leg to replace

Sorry, I'm still not 100% sure what you mean so i've taken a pic, could you point out to me where these isolating valves are.

Also, in the picture where the arrow is pointing there is what looks like a brown sticky coating on the thread, any ideas what that would be, also got some leakage displayed on the pipe cover tray...same colour and directly under where the brown sticky coating is on the thread.

View media item 21733
View media item 21734

 

[garya]

Anyone offer any advice on this one? Thanks.

 

[gas4you]

They look like the valves, but heed my previous warning.

The brown sticky stuff is probably a sign that there is a leak there.

 

[garya]

Called Alpha, don't know why i didn't do it earlier, they sent an engineer next day, opened boiler and replaced air vent(?), i could see that inside the boiler it had been leaking and due to the heat it was evaporating almost immediately, no issues so far but i guess i will know in a couple of weeks time if the pressure has dropped or not.

Thanks for all the replies.