Oil burner too hot

[gavdownie]

Eighty degrees is a winter setting to my mind.
Am thinking I should turn this dial down to four or so as the building is roasting?

 

[SimonG]

Dont touch anything on the burner. Look for a thermostat on the boiler.

 

[gavdownie]

 

[SimonG]

Yes, that one 👍

 

[gavdownie]

Is this the thermostats

This is the thermostat, right?

 

[SimonG]

👍👍👍

 

[gavdownie]

Yes, that one 👍

Thanks pal

 

[gavdownie]

The bit where it says 60 is the water temp, right? And I want to keep it between 60-65 for legionella, right?

 

[SJB060685]

The thermostat on the boiler will govern the temperature of water leaving the boiler. What sort of controls do you have on the system? Are there trv's and room stats etc?

 

[gavdownie]

This is all I can see. Only thermostat in building ive found is on the burner

 

[SJB060685]

Your building is obviously large. You have a really quite large non condensing boiler probably set up for a ∆T of around 11°c across the system. I'd imagine your radiators are sized for MWAT ∆T of 60°c, possibly 50°c. If you turn the boiler stat down to say 75-70°c this will lower the MWT of the rads and the output of them. Unfortunately without thermostatic control over zones/radiators you are going to get these room temperature overshoots and it's still reasonably warm outside (at least it is here in Somerset) so your room temperatures I imagine could easily creep towards 30°c.

 

[gavdownie]

Your building is obviously large. You have a really quite large non condensing boiler probably set up for a ∆T of around 11°c across the system. I'd imagine your radiators are sized for MWAT ∆T of 60°c, possibly 50°c. If you turn the boiler stat down to say 75-70°c this will lower the MWT of the rads and the output of them. Unfortunately without thermostatic control over zones/radiators you are going to get these room temperature overshoots and it's still reasonably warm outside (at least it is here in Somerset) so your room temperatures I imagine could easily creep towards 30°c.

Yes. We experienced the tropical heat when we put it in for the first time yesterday. There are three burners, but this is the only one working. I'll turn it down as you suggested, then plan to close rad valves in all the rooms and open them a bit to get a bit of heat but not too much. Start from zero temo as it were and work up. 60 plus rooms.

 

[SJB060685]

Yes. We experienced the tropical heat when we put it in for the first time yesterday. There are three burners, but this is the only one working. I'll turn it down as you suggested, then plan to close rad valves in all the rooms and open them a bit to get a bit of heat but not too much. Start from zero temo as it were and work up. 60 plus rooms.

The data plate on the burner states your fuel flow ranges are between 9 and 29.5 kg/h on that boiler alone! Without knowing the nozzle size and pump pressure it's hard to say what its actual output is but taking the higher figure as a starting point and a guesstimated combustion efficiency of 90% (probably a little high) then the thermal output of that one boiler alone is close to 350KW.
I don't know where you are located within the UK, nor the design criteria of the system but if your burner is fixed rate, ie not two stage which I don't think it is then going by my example figures above the quick maths suggests your room temperatures could be overshooting by over 10°c. Does that seem about right?

 

[gavdownie]

The data plate on the burner states your fuel flow ranges are between 9 and 29.5 kg/h on that boiler alone! Without knowing the nozzle size and pump pressure it's hard to say what its actual output is but taking the higher figure as a starting point and a guesstimated combustion efficiency of 90% (probably a little high) then the thermal output of that one boiler alone is close to 350KW.
I don't know where you are located within the UK, nor the design criteria of the system but if your burner is fixed rate, ie not two stage which I don't think it is then going by my example figures above the quick maths suggests your room temperatures could be overshooting by over 10°c. Does that seem about right?

Spot on I'd say

 

[gavdownie]

We'll be switching it all off today anyway, it's hit. Thanks for the help pal

 

[SJB060685]

Ok. The boiler thermostat needs to be set slightly higher than any cylinder stat to achieve target stored water temperature. If your cylinder/cylinders stats are set at 60°c then set the boiler stat to 65-70°c. You will still get desired hot water temperatures but at the same time reduce the output of radiators. How much so remains to be seen but should definitely drop the room temperatures down. I must point out though that return water to a boiler or cascade of boilers should not be too low on non condensing units as this can and will cause back end rott that would corrode your boiler/boilers and spring leaks really quite quickly.

 

[gavdownie]

Its hot I mean

We'll be switching it all off today anyway, it's hit. Thanks for the help pal

 

[gavdownie]

Ok. I'll have a look tomorrow. Thanks pal

Ok. The boiler thermostat needs to be set slightly higher than any cylinder stat to achieve target stored water temperature. If your cylinder/cylinders stats are set at 60°c then set the boiler stat to 65-70°c. You will still get desired hot water temperatures but at the same time reduce the output of radiators. How much so remains to be seen but should definitely drop the room temperatures down. I must point out though that return water to a boiler or cascade of boilers should not be too low on non condensing units as this can and will cause back end rott that would corrode your boiler/boilers and spring leaks really quite quickly.

 

[gavdownie]

Someone left the heating on today and it was roasting inside again as a result. Going to drop to 65 degrees. Rads on all wings were hot. Going to do a rad count next week, there's a mix of old and new.

Found an old oil tank. Ten cm depth in the bottom. Assuming it's level there's near 600 litres in it, but getting that out might be tricky if it's even worth it, and of course all the muck in the bottom too. It's an old,

old tank.