Setting firing rate on gas boiler

T. Riley

Now that I've determined that my boiler has been sized to the proper square feet of steam required, how do I determine that its' firing rate is correct? Or, better yet, how do you set it? The gas valves are Honeywell V800 series.

jim sokolovic

Do you have the Instruction Manual...

for the boiler? It should provide the manufacturer's recommended procedure for setting the gas valve properly. If you do not have it - post the manufacturer, model, and gas type here, and probably someone will help further. Slant/Fin recommends clocking the gas meter for 3 minutes, then take the # of cubic feet measured in that time, multiply by 20 (to give what would be a full hour's worth), then multiply by the heating value of the gas (usually 1000 BTU/cubic foot, but can vary by altitude or other factors). This gives the BTUH input rate.
Not all companies recommend the same gas valve outlet pressure for their boilers, but generally 3.5" for Natural Gas, and 11" for Propane are the most common specified.
A full checkout of the system (CO testing particularly) by a professional is always in your best interest, if you are a homeowner or do not have all the proper tools for this.