Indirect cylinder coil leaking ?

[jirams]

Gravity Indirect HW cylinder fed by Baxi 552 BBU + circulating pump + 9 rads.

Are there any 'standard' symptoms or 'tests' that would confirm (or otherwise) that the heating coil in such a system was leaking into the HW part of the cylinder?

There is no evidence of expansion into the F+E tank nor expansion of the HW system.

The reason for ? is that when the boiler is burning, I hear noises which sounds like air causing turbulence but all the rads do not need bled and as I said above there is nothing being ejected from expansion pipes. I don't hear the noises in attic - they are heard downstairs in house and with ear against chimney breast adjacent to pipe runs to BBU.

 

[WHPES]

Only way for sure to check the cyinder coil is to disconnect the flow and return from the cylinder. If it is leaking bad it will continue dripping from the bottom. Otherwise cap off one end and pressure test with a plumbers test pump.

 

[jirams]

Only way for sure to check the cyinder coil is to disconnect the flow and return from the cylinder. If it is leaking bad it will continue dripping from the bottom. Otherwise cap off one end and pressure test with a plumbers test pump.

I do recall a couple of years ago that when I was replacing a blown electrical immersion heater in this very cylinder I was getting the cylinder filling slowly when I had the immerser out - I put this down to being a leaky feed hand tap from the CW storage tank which was VERY stiff to rotate (35 years old).

I am reluctant to start on such old compression fittings - is coil leakage a common fault?

Perhaps I could turn off mains, drain CW storage, empty HW cylinder via taps and observe if F+E tank empties due to it trying to fill HW cylinder via leaky coil?

 

[WHPES]

You could try that but you will need to leave it quite some time to notice a difference.

Loads of crud in the F&E tank is usually a sign of a leaky coil as the radiators will be in a bad way.

 

[jirams]

You could try that but you will need to leave it quite some time to notice a difference.

Loads of crud in the F&E tank is usually a sign of a leaky coil as the radiators will be in a bad way.

Yeah - due to constant top up with fresh oxygenated water.

The system is very old and has not been drained for many years (would you believe around 25 years?) - the F&E has some fine sediment at bottom but is showing clean water - perhaps a good sign?

I appreciate very much your posts ;0)

 

[kirkgas]

if the coil is split i would expect the domestic hot water to be black from the heating sludge, or to smell funny due to inhibitor,
out of interest where are you based im in Coatbridge

 

[WHPES]

Depends which way the pressure is - which tank is highest?

 

[jirams]

if the coil is split i would expect the domestic hot water to be black from the heating sludge, or to smell funny due to inhibitor,
out of interest where are you based im in Coatbridge

Stra'ven - DHW is clear and no smell - this system has never had inhibitor in 25 years - don't believe in these newfangled ideas *<:0) - thanks mate.

 

[jirams]

Depends which way the pressure is - which tank is highest?

The F+E and CW storage sit side by side on the same joist in attic.

 

[WHPES]

Therefore the flow would be into the F&E tank as the water level in the DHW tank would be higher. Water would be coming out of the F&E overflow if this was happening.