Riello RDB 2.2 oil pressure fluctuating.

[quattro64]

Hi Everyone
I am relatively new to oil, have done my exams and registered with OFTEC but am lacking general experience. I have a boiler issue and wondered if someone could help.
The boiler is a Worcester danesmoor 18/25 fitted with a Riello RDB2.2 and supplied via a Tiger Loop. The boiler is just over a year old and was occaisionaly cutting out some times once or twice in a couple of weeks and then would run fine again. Recently it has been getting more frequent.
I looked at the boiler yesterday, changed the oil filter. connected up my presure gauge and plugged in the FGA.
The oil pressure was a little bit low (105psi) and the needle on the gauge was jumping around a fair bit. I have tried to increase the pressure but the needle on the guage keeps on jumping around. It also took quite a bit of turning to bring it up to 125psi. Does this indicate a faulty pump or another problem? On other boilers I have worked on the pressure guage normally stays quite stable.
Many thanks in advance for any help.
Regards.

 

[DustyM]

Hi Quattro,

From my experiences that could be caused by several things, although assuming a faulty pump is the logical thing to do, you should also check out the pump drive coupling to see if it is worn and perhaps the pump is slipping. Are there any other filters in the oil supply line? Have you checked the pump filter itself? Have you checked all the oil connections to ensure they are secure and not allowing air to be sucked into the line. You should also confirm that you have good fuel flow to the pump, and that there's no blockages/partial or other wise? I'm not experienced enough with Tiger loops to advise there, there will be other forum members who can I'm sure. It could be the pump, but........................

 

[kimbo]

When the boiler is running check and see if there are any air bubbles going into the tigerloop, air would cause the fluctuation, it could also be the pressure adjustment which is faulty which would also account for the lack of fine adjustment. If air is showing in tigerloop you will need to check the integrity of the joints on the suction side.

 

[quattro64]

Thanks for replies, I am going back this afternoon and will check all pipe work.

 

[kimbo]

If all else fails it willbe a new pump

 

[Bunker]

As above, probably pump but check supply including flex - is this twisted? What sort of filter is it - if its those awful tank ones with the red cap on the sight guage, it could be the metal strainer underneath being blocked up.

 

[Dotty]

Also check that your valves are open and that there are no blockages in the tank. Check the tank vent too.

Had something similar a while ago, kids had mostly turned the valve off at the tank.

 

[quattro64]

Thanks for all your replies, it turned out there was another filter 1/2 way on the supply line right a the back of the house obscured by a shrub!! the current boiler was installed in a different position and the original line extended and run underground round the side of the building. When it was done the old filter was left on and was filthy. Now thats been sorted the boilers running fine.
Cheers.