Danfoss Type BFP 31L reading 0 bar on oil burner

grill · 21 Jun 2007

Alright guys,

Was just out an annual service on a Nuway Boxer Oil Burner and there and was going through the regular checks. Burner seems to be working away merrily.

The pump type on the burner was Danfoss Type BFP 31L and when i screwed my pressure guage into the port labelled P on the side of the pump i got a reading of 0 bar. Turned the adjustment screw slightly (noting where it was!!!) and still no reading on the guage.

I came home and stuck my gauge onto my burner and everything is reading fine with the gauge.

Any ideas why i would be getting a reading of zero at this point? There definately was oil at this test point as well.

Your thoughts would be most welcome.

Grill

JPH/01 · 21 Jun 2007

if you are ever in doubt as to where to fit a gauge , pull the bleed nipple out and fit gauge there.

Agile · 21 Jun 2007

Have you ever coupled to a pressure gauge at this point on that model before???

It sounds as if its not the correct place!!!

Tony

grill · 22 Jun 2007

Hi Tony,

I was thinking that myself but on teh side of the pump you a test point that says P and the test point below it says V and these usually signify your pressure and vacuum test points??

I was on the Danfoss website last night trying to get the tech spec for the pump but couldnt seem to find it.

If i come across one again ill try it on the bleed nipple.

Is there anything else it could be??

grill

JPH/01 · 22 Jun 2007

The bfp 31 is no longer made, a bfp 21 would replace it when needed,
are you sure that the gauge manifold valve was open or ptfe tape was not blocking inlet to gauge.

grill · 22 Jun 2007

definately,

As i said above i came home and stuck the exact same gauge into my own pump and it was reading no sweat.

I know it doesnt really make any sense.

Was thinking that maybe a tigerloop might have been fitted at some stage and the wee grub screw you put in might have re directed the flow but this don't make any sense either, especially as there was oil coming out of the test point.

Must be Gremlins i suppose. Just a bit annoyed as i couldn't fully set the pump up as i wanted and have to assume it at teh right pressure!!

Grill

JPH/01 · 22 Jun 2007

If the grub screw or horse shoe washer was fitted to a pump set-up for 1 pipe the result would be instant death for the pump!.

gasandoilman · 22 Jun 2007

Is it a two pipe or single pipe system?

Did u do any other readings eg smoke,co,co2 and flue temp?
and can u see the flame picture on this boiler
if so dont worry about the presure but it does sound strange
i hane not had this happen in 15yrs ??

grill · 22 Jun 2007

Gas and Oilman,

Nah it is a single pipe system. Was just thinking someone might have switched pumps at some stage. Clutching at straws!!!!

Did the smoke test and it was fine. Just like to tick all the boxes!!!,

What do you use to test Co Co2 and temp levels and what would be your reccommends values?? I service gas boilers as well and have an electronic flue gas analyser but apparently it is not good to use these on sooty oil boilers???

I have only recently started servicing opil boilers and still have a few things to learn

Yeah it is a strange one alright

grill

gasandoilman · 22 Jun 2007

I use the flue Analyser on both it's ok as long as you do a smoke test first!
if clear then do test.
You can buy a wet kit thats for oil its a bit like a u gauge with red liquid in
u pump it 10 times then turn over it gives you a co2 reading
its old way of testing but good back up when Analyser is getting calibrated

The readings are in the MI about 12%co2 flue depends on conventonal or bf about 190c

grill · 22 Jun 2007

Cheers for that.

JPH/01 · 22 Jun 2007

18 pumps for a wet kit and that red liquid is highly corrosive and poisonous.

gasandoilman · 22 Jun 2007

Sry my mistake 10 pumps for smoke and 20 pumps on the wet kit!
yes it is corosive not sure about poison iv not drunk it

you can buy bottle top up from parts centre e.c.t.

wilhelm · 22 Jun 2007

grill, you definatley must have had it in wrong port. check it again when you get called back

was it in a church crypt? ..... invariably the nuway burner is fitted on some monster of a boiler in some poxy location. (sorry God)

yes i have seen them on a trianco tro, in a semi..............before i get flak.

grill · 24 Jun 2007

Right guys,

I have got to the bottom of the problem and my face is defo red.

When i said i checked the pressure gauge on my own burner i forgot that i didnt have the maifold attached to the guage at the time as it is a nice wee Sterling burner which has easy access to the pressure port. Checked the manifold and it was indeed blocked as previously suggested.

Apologies if i have wasted your time and caused numerous head scratching!!!!

Just while we are on the subject of pumps how do you know that a pump is done?? I know you can go through the checklist of problems and work back but i changed a pump the other day and the shaft still spun i.e. wasnt seized up. Changed the pump and away she went. Is it a case that it either pumps or it doesnt??

Thanks again

Grill

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Danfoss Type BFP 31L reading 0 bar on oil burner

wilhelm

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