central heating boiling question

Do you mean water pressure

or oil burner pressure if so your boiler service man will show you if youbask him
It depends on whether it is 28 sec kerosine or 35 sec Gas Oil, Diesel
 
It's the oil pressure at the firing jet. When I installed this boiler there was an official set up sequence for approx 5bar for fuel oil and it has been working for the last 6 months at this pressure, but I noted yesterday that written on the boiler round the back is a label saying the maximum pressure should be 3 bar for fuel oil. Should I reduce the pressure?
 
Are you certain that the label at the back of the boiler refered to oil burner pressure

and not max water pressure.

What makes are the boiler and burner
 
The boiler is a Firebird Popular 90, and the burner is a Riello 40. It has a label on it that says Max Operating Pressure is 3 bar. What worries me is that they also supplied a circuit diagram and install instructions (RIELLO 40 G3B code 3743712 TYPE 437T1) which says as I read it, For gas oil 12 bar and up to 10 for kerosene. This to me seems ludicrously high and would require the adjuster nut to be fully in, and then might not be obtainable. This is an open expansion central heating system so water pressure should not be a problem. The only thing I can't tell you is the type of nozzle but I can't see how this would effect the pressure as it's still the original. Thanks for your help so far.
 
An experienced oil burner installer will always carefully read and be guided by istallation instructions that come in the box with with the burner.

Label attatched to the boiler may refer to max water pressure and so on.

I would suggest that you ask the supplier to send someone to commision the burner for you.
 
That's a bit difficult as the kit sat in garage for 6 years and the supplier has now moved on. Thanks anyway.
 
This was set up by the supplier, all other parts of the system where already there, checked and working with another boiler. As the boiler is only being used for heating and not hot water and has not been run for over a year (we are facing south with large windows and an open fire) it has never been required. As coal and age are increasing it was decided to look at the system. It was then that I read the instructions and found the differance. I know the rest is ok and feel 100 euro for a visit to check the pressure was a bit high, hence the question. I will have to ask elsewhere. Thanks.
 
David Walker said:
It's the oil pressure at the firing jet. When I installed this boiler there was an official set up sequence for approx 5bar for fuel oil and it has been working for the last 6 months at this pressure, but I noted yesterday that written on the boiler round the back is a label saying the maximum pressure should be 3 bar for fuel oil. Should I reduce the pressure?
Click to expand...

Where are you seeing this pressure reading of 5 bar?

I am quite certain that your BOILER will not have a label that will state 3 bar for fuel oil. It may have a label that will state "max operating pressure 3 bar" but that is the pressure of the water in your heating system which with an open system will generally not exceed that (3 bar).

So back to the question of your heating system being set at 5 bar for fuel oil. Without a totally uneconomical air setting on the BURNER 5 bar for the oil burner would not run very well. Buy a 6 euro oil pressure gauge and run the burner, you will then have the pressure reading for the oil and have saved 94 euro.

Remember you should draw a big black imaginary line between the BURNER and the BOILER.
 
Thats exactly what I have done, I purchased a pressure gauge, fitted it to to correct point and started the boiler. What I still don't know is what should be the correct working pressure for GAS OIL. I can reduce the pressure with the adjuster nut until it won't fire up and can turn it up to 8 BAR but what is correct setting. I suspect that a lot of units are even checked as long as they fire up. Certainly I've never seen a service guy using one. Perhaps I have only seen a bad bunch. I've even been told to watch the colour of the flame to get it right.As I said the official set up says 8 to 12 bar but it all seems very vague. If the pressure is high are you likely to be using more oil, although the temperature may be higher do the sums work out the same.
 
I had this problem some years ago, I could not set the oil pressure at the burner by hit and miss, it either would not fire or would not stay firing, in the end I fitted a pressure gauge in the supply line and set it to 80 psi as far as I remember, it was fine after that. Setting the correct pressure is critical, I think there is a connection on the pump block for a pressure gauge but I fitted it in the line via a tee piece.

On another topic: should there be vapour at the flue outlet to atmosphere? it is pouring out, the ground under the outlet is always damp. Thers is a condensate drain pipe almost at ground level, a little water comes out of this pipe. The Plumber who installed it said this was because it was new, that was six weeks ago. I understand a "Condensing Boiler" has the central heating return line passing back through the flue, picking up some heat which would otherwise be going to atmosphere, therefore making it more efficent but Iv'e never seen this before and I am sure there are hundreds of them around.
 
stoker, what type of boiler have you and how long is the flue? if the flue is longer than standard a condensate trap has to be fitted, it shouldn't happen like you describe and will shorten the life of your boiler as the condensate is slightly acidic and will rot the inside of the boiler after time.
 
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