Oil Burner Fuel Pump return/bypass port Leaking

airliebeach

Hello,

this port is leaking fuel.

Its a danfoss pump.

Single pipe, connected to inlet.

The port in question is not used & has whatever bung that came with the pump still inserted as seen in pic below.

Just started leaking this week after 3/4 years of service.

What could cause this?

Time for a new pump or something simple to fix?

Any advice would be greatly appreciated.

Wearb

That looks like a plastic bung. Whoever fitted the boiler should be called back to replace it foc.

airliebeach

Thanks for advice

Tis plastic

I think standard with the Elcos

Fixed by resealing with uni red and hemp.

John.G

What is the purpose of this, "adjustment" is written on the cover, if its for adjusting the pump pressure then there should be no "leak"?.

jimf

no no no take wearb advice

that should be a steel plug

get fitter back asap to sort foc

jimf

https://www.boards.ie/discussion/comment/121892359#Comment_121892359

its the plug in front of where the hose is fitted we are discussing john

declan b

https://www.boards.ie/discussion/comment/121892262#Comment_121892262

The plastic bung comes with the burner to cap the pump. its is removed when burner is fitted and the flexible oil hose is then fitted in that port on the pump.The way you have it is an accident waiting to happen. its a danfoss grub screw that should be there. [it is not sealed by the treads or hemp either]

John.G

https://www.boards.ie/discussion/comment/121892886#Comment_121892886

From post #1 "Single pipe, connected to inlet. The port in question is not used & has whatever bung that came with the pump still inserted as seen in pic below."

I see, so shouldn't the so called bypass screw, that I prefer to think of as the the bypass blanking PLUG screw be confirmed NOT screwed in here, otherwise the oil cannot recirc inside the pump and the pressure will be huge, mine, shown below (in a 19 year old Riello G5X) is still taped on to to my instruction book with obviously a steel blank plug to stop any leakage, that plastic blank maybe infers that the bypass screw is still inserted so ensure its not before putting a proper steel blank on??.

Riello G5X Internal By Pass PLUG Screw..jpg

jimf

the riello pump comes with the bypass screw not fitted hence you have it as advised

the danfoss pump comes with a horseshoe type bypass but its fitted already and used when set up as 1 pipe system

the horseshoe is removed when the burner is set up as a 2 pipe

can be confusing

jimf

should have said the bypass on the danfoss is fitted in the pump body and not in either of the flow or return ports

John.G

So, since it came configured as a one pipe system, they must be happy that a plastic plug is adequate?,

Wearb

https://www.boards.ie/discussion/comment/121895233#Comment_121895233

No. People (inexperienced) often just remove the steel plug from the inlet and fit the oil hose leaving the plastic plug in place. Plastic plug should be replaced with the steel plug. Riello now have the plastic plug coloured yellow to highlight its existence.

Service techs have suggested that the plastic plug is a cost saving plan by some bean counter. Whatever the reason, it should be replaced.

John.G

Are you saying there's a steel plug in the inlet?, you would think the plastic plug would be in this port as there will allways be a (inlet) pipe connected here,.

Looking at the picture below, it shows the horseshoe washer and blank plug, wonder if this is metal with a plastic "dust cap" outside, its hard to imagind danfoss supplying a plastic plug without a warnig re replacing it with a steel one.

Wearb

I don't come across Danfoss pumps very often. Last one I fitted was years ago.

That port (on 1 pipe system) is only subject pressure from supply head. Of course -in some circumstances- that can be substantial.

Wearb

Here's an old pump with the yellow plastic plug.

John.G

That makes the best sense, either they shipped the pump with the plugs in the "wrong" ports or on installation both plugs were removed for one reason or another, the inlet pipe was connected up and the plastic plug was inserted in the bypass port.

declan b

https://www.boards.ie/discussion/comment/121898045#Comment_121898045

id agree. The plastic bung is always is always fitted in the flow of the pump.It is just simply removed and discarded and the flexible oil hose is fitted in its place.i have never seen the pump manfactures to make a mistake and fit the bung in the wrong port

jimf

https://www.boards.ie/discussion/comment/121898045#Comment_121898045

that is exactly what happens

Wearb

https://www.boards.ie/discussion/comment/121900493#Comment_121900493

Isn't it amazing the way we come across this every now and then, even though it takes more work to do it wrongly 🙄🤪

jimf

https://www.boards.ie/discussion/comment/121900567#Comment_121900567

ya at least 2 or 3 every year

airliebeach

Interesting conversation lads.

Yee have me slightly worried.

Leak is gone now anyway, I'll mention it to the next guy to service it.

Thanks for the info.

declan b

https://www.boards.ie/discussion/comment/121907309#Comment_121907309

id be mentioning it to the last guy that serviced it ! . or the installer !