Oil-fired boiler - baffling problem...

Sanguine Fan

We have an external oil-fired boiler located in a corner quite near the rear of the house. I have no idea what make it is. It is rectangular box about four feet high with the housing made from what looks like galvanised steel. (see first photo attached.)

Recently I noticed a wet patch on the ground at one corner of the boiler. At first I thought it might be a water leak but the smell was enough to tell me it was kerosene. I turned off the tap at the tank and called an engineer.

He replaced a section of pipe from where it enters the boiler housing to where it connects into the burner. The old section of pipe he removed was badly kinked but there was no obvious hole or perforation from which oil would have leaked. I thought perhaps it had been badly connected to the burner and oil had seeped along between the inner copper pipe and the outer plastic casing until it emerged through a hole in the plastic casing. This seemed like the only possible explanation.

However, the wet patch has reappeared but gets no bigger when I turn off the tap at the tank. So, somehow oil is escaping from the pipe somewhere within the boiler, even though that section of pipe has been replaced. The connection to the burner is perfect - no sign of any leak there.

The problem is that the boiler housing is constructed in such a way that it cannot be completely disassembled. So I can't easily get down to the point where the source of the leak seems to be. Yet the situation seems simple. The pipe enters at one end of the boiler and reappears at the other where it is connected to the burner. There is no flaw along the intervening section of pipe. Yet oil is leaking out somehow.

I attach two photos which I hope will make the situation clearer.

Has anyone experienced anything like this or is there something obvious I have missed?

Many thanks.

JamesM

If there is a leak where the pipe joins the tank, oil can run down the pipe inside the plastic covering.
Most likely it is at the burner. The burner is the red box. If the top of the burner is dry, then it is not leaking from the filter or the fire valve. Put your hand under the red box. If it is wet, then the leak is from inside the box. Take off the cover - 3 screws. The oil line goes into the oil pump on the left. Check this for leaks. There are allen screws and plugs. These may have been loosened when someone was bleeding the system, after running out of oil. Do not turn the screw at the front, which is easy to turn, it is the pressure adjuster. There is a brass hydraulic jack on the rhs of the burner. It is the most likely cause of the leak, and needs to be replaced. It is a seal which leaks, but the whole fitting has to be replaced. It is easy to do.
Jim.

Sanguine Fan

Many thanks for that tip Jim. There is indeed a film of oil on the underside of the burner so that's where the problem must lie. The ground on which the boiler rests is not level so that would explain why the leak is pooling on the left side - the burner being on the right in the photo.

jamesbuild

Without seeing it I would suspect that the burner has been bled, maybe more than a few times. There is a little copper washer on the bleed screw (nut) which may be missing or damaged. Also, its hard to bleed without making a mess. If you want to clean the area, fairy liquid and plenty of hot water will do it..

Sanguine Fan

Thanks for your post. Yes, that turned out to be the problem and the washer has now been replaced.

crosstownk

jamesbuild wrote: »

If you want to clean the area, fairy liquid and plenty of hot water will do it..

Clean it completely and then keep a close eye on it so as you can see the exact area where the leak is originating.

Stinky45

Jim...re: small brass hydraulic piston that lifts the air vent to the burner...you are spot on...my mothers unit leaked there and mine is also leaking at that very spot. You say only new brass piston can fix. I took it apart and why is the rubber sealing washer akin to that of a bike pump not available...OR...can vent be locked open and bypass the piston???

[mod] please note that this thread is over four years old![/mod]

Billy Bunting

RIELLO RAM SEAL 3007132

Stinky45

Thanks Billy

sully123

Stinky45 wrote: »

Jim...re: small brass hydraulic piston that lifts the air vent to the burner...you are spot on...my mothers unit leaked there and mine is also leaking at that very spot. You say only new brass piston can fix. I took it apart and why is the rubber sealing washer akin to that of a bike pump not available...OR...can vent be locked open and bypass the piston???

[mod] please note that this thread is over four years old![/mod]

Hey stinky,

Hi have the same issue. the leak is coming from the under side of that small brass unit.

Did you manage to stop it?

Billy Bunting

If you posted on the P&H forum you would find that the problem is the hydraulic seal within the ram, simple job part costing €1

Stinky45

Yes I fixed it with some neoprene rings...they very slightly restricted the travel of the vent flap but I adjusted that too. After the fix I became aware of the part being available ...very cheap and fairly easy to replace.

Billy Bunting

Stinky45 wrote: »

very slightly restricted the travel of the vent flap but I adjusted that too..

If you have made any adjustment you will require the burner to be set up with a FGA to be sure its correct, Carbon Monoxide is a silent killer.