Gas BTU Appliance Question

BrianW83

I have a 450k BTU gas meter coming into my home. I have a Utica DV200B 199k btu input boiler and this does my heat in the winter and my hot water all year round. I am looking to put a Hayward 400k BTU heater in for my pool. My question is when the boiler is heating up my hot water is it really using the full 199k BTUs? For the most part these appliances will not be running together at the same time only once in a while. I am trying to figure out what the negative side of having these two installed together will be. Will it just take longer to heat the water?

if not I know I can put in a Hayward 250k BTU heater and have the 199k btu furnace and be within my 450k BTU meter.

I am not looking into getting a new gas pipe/meter from the street there is to much involved with it.

Jamie Hall

It might work. More likely not. What happens is that there will be much greater pressure drop though the meter. Now if your pressure regulators can handle that, you might be OK. It's much more likely that trying to put half again as much gas through the meter will drop the pressure to point where neither the boiler nor the pool heater nor the water heater will work — they will lock out on low pressure. Any pilot lights will go out. And you will need to get the gas company to come and restore service — which they won't, as your system will be overloaded.

And yes, your 199K heater does use 199K BTUh of gas when it's running.

mattmia2

depending on the pressure in the street and the size of the service lateral it is very likely you can increase the service by just replacing the meter and the regulator. If you figure the pressure drop of the meter at the higher flow and size the piping accordingly to keep the pressure to the appliances sufficient it should work if you can make that math work.

Mad Dog_2

We must design a natural gas system for worst case scenario. In NYC & NYS, the Building depts & Gas utilities want the full load calculation and enforce it. This comes up all the time, and the same reasoning it cited. Upgrading the meter & piping and testing add considerable cost to a project. Mad Dog

BrianW83

thank you for your response I think I will stick with the 199k boiler and the 250k btu heater so that I am covered and don’t have to worry about it.

EBEBRATT-Ed

@BrianW83 make sure the pipe to the pool heater is sized properly considering it is usually a long run.

EdTheHeaterMan

In some locations, there are gas companies that offer a separate meter for the pool. Your high pressure main from the street to the meter(s) location is usually large enough to handle both meters. Check with the Gas Company on this.