Frost Protection on outside oil boiler module

[andyr123]

in the instructions on our Grant Euroflame outdoor kerosene oil boiler it says that a pipe state fitted to the return water pipe may be fitted to offer frost protection and that it shall be set at 30 degrees centigrade.

If water freezes at 0c i wonder why they say to set the stat at 30c ? - and wouldnt that use more oil in the end?

 

[polesapart]

More likely the frost stat is integral (wouldn't you fit one as standard in a water filled expensive thing that lives outdoors) ; the pipestat is to reduce the amount the boiler fires after being triggered by the protective frost stat.

 

[leakydave]

Your boiler has a frost stat which fires the burner if the temp inside the boiler casing gets below about 5°C. To stop if firing for long periods, a low-limit stat can be fitted to the return pipework in the boiler, so that when the return temp reaches 30°C it will turn the burner off.

 

[oilboffin]

You'll be in a world of pain if you don't have a frost stat.Bob

 

[andyr123]

Thanks very much all - re wiring of the pipe stat is Diagram 1 right or Diagram 2 correct thanks?

 

[Terrywookfit]

2

 

[Wildcat1961]

With diagram 1 frost stat has no function.

 

[oilboffin]

This may seem a daft question but on all the external grant boilers I've fitted a frost stat has always been fitted and I've been asked by grants a time or two to replace the frost stat under warranty when they've played up,and if factory fitted you'd think it would be fitted in a way so as to be economical would you not.Bob

 

[andyr123]

i hear/read 2 different settings for the frost stat some sites say 5c .. then some say 0c - i have just set ours at 3-4c - on some grant condenser boilers (could be vortex) they have a non adjustable frostat set at 5c at the factory.

If you had a pipe stat wired up as in diagram 1 at 30c I shoud think you could do away with a frost-stat altogether couldnt you because it will always be keeping the return water at 30c ? (and consequently the inside of the boiler outdoor module above freezing)

 

[oilhead]

Only for as long as the heating is timed. The frost stat overrides all timer setting.

 

[Wildcat1961]

If you had a pipe stat wired up as in diagram 1 at 30c I shoud think you could do away with a frost-stat altogether couldnt you because it will always be keeping the return water at 30c ? (and consequently the inside of the boiler outdoor module above freezing)

Burner would run whenever return temperature reached 30c or lower (fuel wastage).

 

[andyr123]

Only for as long as the heating is timed. The frost stat overrides all timer setting.

ah right , because its on the permanent live? - so if you wired the pipe stat at 30c on the permanent live and not the switched live then that would work ... but as wildcat pointed out - fuel wastage

 

[oilboffin]

The boiler will only run for a very short while.Bob

 

[Wildcat1961]

The boiler will only run for a very short while.Bob

Back end rot can destroy a heat exchanger within a short space of time (SE)

 

[oilhead]

Just wire a frost stat independent of your timer, set a 5o in parallel with a pipestat on the return at 30o or so. Your boiler frost stat is already installed for the former, just limit with a pipe stat on the return. You know it makes sense.