Danfoss oil pump on burner

FFS Decreasing pressure will not make any difference.
You must have an alignment issue or a tight gear set in the pump.....Does it feel tight to turn it.??
 
Terrywookfit said:
FFS Decreasing pressure will not make any difference.
You must have an alignment issue or a tight gear set in the pump.....Does it feel tight to turn it.??
Click to expand...
The problem we have is that the 'new' pump gets hotter than the old pump. You and I have experience of pumps on many burners whereas the OP only knows this one. We both know solenoids get too hot to touch,(what is the cap that holds it on?) We also know that pumps get hot. The impression of heat is very subjective, you and I may consider it normal. He only has a defective pump to compare it with, and I doubt if he has been feeling the pump for the last several years. Personally, if it runs for 15 mins, I doubt if it would get any hotter. We also don't know how hot the motor gets, that may be transferring to the pump. Either way, if he's replacing the boiler in a few months, the problem will go away.
 
I must have missed the new boiler bit !!! .???
The fact remains that there was no excessive heat with the old pump,Therefore it must be a pump, dog or alignment problem which you have already told him.
 
Terrywookfit said:
FFS Decreasing pressure will not make any difference.
Click to expand...
Alright calm down. Nice of you to reply but no need for the attitude. More pressure => more resistance => heat. We see it all the time - in electrical circuits, friction systems such as brakes, clutch, gas flow etc, ever pumped up a tyre? So it's a perfectly reasonable question and no harm in getting a second opinion. The pump isn't tight - won't freewheel but not tight. I see no reason why the new pump doesn't align but the old pump was okay.

oilhead - the cap is a nut that holds the solenoid to the valve that it controls. I have felt the old pump before it became defective and it didn't get hot at all. Nor did the pump on my friends burner. I won't be changing the boiler in a few months as the council have put planning applications on hold and I'll have to endure another winter at least before building starts.

John - You can get a firm grip on it for about 3 seconds before it gets to hot to hold. I suppose I'll just get the pressure adjusted and let it run for a day or two and if it fails it fails. At least if that happens I'll have time to sort out something before the really cold weather kicks in. Motor doesn't feel hot.

Anyway I can sense some you are getting fed up with this thread so maybe best to call it a day on this one. Thanks all for your responses. Much appreciated.
 
TonOfSand said:
Alright calm down. Nice of you to reply but no need for the attitude. More pressure => more resistance => heat. We see it all the time - in electrical circuits, friction systems such as brakes, clutch, gas flow etc, ever pumped up a tyre? So it's a perfectly reasonable question and no harm in getting a second opinion. The pump isn't tight - won't freewheel but not tight. I see no reason why the new pump doesn't align but the old pump was okay.

oilhead - the cap is a nut that holds the solenoid to the valve that it controls. I have felt the old pump before it became defective and it didn't get hot at all. Nor did the pump on my friends burner. I won't be changing the boiler in a few months as the council have put planning applications on hold and I'll have to endure another winter at least before building starts.

John - You can get a firm grip on it for about 3 seconds before it gets to hot to hold. I suppose I'll just get the pressure adjusted and let it run for a day or two and if it fails it fails. At least if that happens I'll have time to sort out something before the really cold weather kicks in. Motor doesn't feel hot.

Anyway I can sense some you are getting fed up with this thread so maybe best to call it a day on this one. Thanks all for your responses. Much appreciated.
Click to expand...

https://www.google.co.uk/url?sa=t&r...20MANUAL.pdf&usg=AOvVaw2mmL5EXLLBIvjGidkwl4v5
For your edification Have a look at page 14 !! FFS;):whistle:
 
TonOfSand said:
Alright calm down. Nice of you to reply but no need for the attitude. More pressure => more resistance => heat. We see it all the time - in electrical circuits, friction systems such as brakes, clutch, gas flow etc, ever pumped up a tyre? So it's a perfectly reasonable question and no harm in getting a second opinion. The pump isn't tight - won't freewheel but not tight. I see no reason why the new pump doesn't align but the old pump was okay.

oilhead - the cap is a nut that holds the solenoid to the valve that it controls. I have felt the old pump before it became defective and it didn't get hot at all. Nor did the pump on my friends burner. I won't be changing the boiler in a few months as the council have put planning applications on hold and I'll have to endure another winter at least before building starts.

John - You can get a firm grip on it for about 3 seconds before it gets to hot to hold. I suppose I'll just get the pressure adjusted and let it run for a day or two and if it fails it fails. At least if that happens I'll have time to sort out something before the really cold weather kicks in. Motor doesn't feel hot.

Anyway I can sense some you are getting fed up with this thread so maybe best to call it a day on this one. Thanks all for your responses. Much appreciated.
Click to expand...
3 seconds - bloody hell :eek: Something seriously wrong there!
I'd bite the bullet and get another genuine Danfoss pump.
For what its worth, and in my limited experience compared with the other guys, I've found burners difficult to start if the pump was tight (instant lockout) and on one occasion wouldn't spin fast enough to deliver the required pressure.
For sure I'd be interested in the outcome.
John :)
 
The way in which this oil pump works, with helical gearing, increasing or decreasing pressure will not increase or decrease heat. The gears just circulate in the oil and however much you need is controlled by the outlet setting. Comparing with air pumps or electrical circuits is not valid. If the helical gears are tight, then you get heat from friction.
The solenoid is a different proposition. Solenoids get hot from the electrical resistance in operation. I would not like to hold one for more than 2 or 3 seconds.
 
oilhead said:
The way in which this oil pump works, with helical gearing, increasing or decreasing pressure will not increase or decrease heat. The gears just circulate in the oil and however much you need is controlled by the outlet setting. Comparing with air pumps or electrical circuits is not valid. If the helical gears are tight, then you get heat from friction.
The solenoid is a different proposition. Solenoids get hot from the electrical resistance in operation. I would not like to hold one for more than 2 or 3 seconds.
Click to expand...
A solenoid coil only takes about 100ma .After 1 5 mins it should only be warm to touch. They are only rated to 50*c.
 
oilhead said:
Which is why Danfoss uprated their Diamond coil to 70c
Click to expand...

Yes but the 50° coil has worked ok for 20 odd years...…..some lasted 10 to 12 years.

If they had run too hot to touch, they would have failed much more frequently.

I tested one today on my coil test rig . After 30 minutes the coil could be held without discomfort.
 
For anyone still watching this thread. I was talking to a plumber who looked at the pump and pointed to the 'L' on its model number and said this is a left sided pump. The pump was fitted to the right side of the burner. He was unsure if the L meant the pump should be on the left of the motor or the motor on the left of the pump and suggested it would still 'work' but could be the cause of the problem if it was the wrong way round. Please feel free to chime in on your thoughts though it's no longer a problem now as I have got gas in, but I'm still curious, as it's is my nature. Again, thanks everyone for your time in responding - much appreciated.
 
Usually if the pump is on the left side then the pump spins right.If it’s on the right it spins left. Bob
 
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