Gas boiler with domestic coil

Tony_4

dont you see many gas boilers with domestic coils. I am not a fan of domestic coils but this question has come up several times with other contractors and I would like to hear some other opinions.
I believe it is because a gas water heater is less money than a coil and controls and with oil it is the opposite.
Thanks

B. Tice

Tony, the way it was explained to me is that the AGA decided years ago that they would take the position of the heating and water heating should be seperate units.Therefore, the manufactuers followed suit by producing small BTU boilers with the assumption that a seperate dirct fired water would be used.(what I mean is that you can buy small gas boilers for small houses if needed)The oil tradtion has been heat and domestic with the same unit.

Dale

I've seen many many dead coils.

Where I'm from the water is fairly hard, 26 - 32 grains, the poor flow rate and need to acid clean the coils makes most owners abandon them. If you have gas it's much cheaper and easier to just put in an inexpensive gas heater, even if you use a softener why keep the boiler hot all summer?

Unknown

Gas Fired Boilers & Submersible coils

Are the same as oil fired boilers with domestic coils.

In todays market people look to get the biggest bang for the buck. Fuel economy in heating buildings drive the industry. When you size a boiler for steam heating you need to make sure that the boiler will heat the house and supply domestic hot water.

Each gallon of domestic hot water production requires
50,000 BTUH for a 100 degree rise in temperature.

In most older heating systems the piping pick up factor was the reserve that would provide some of the hot water.

In a steam system that required 100,000 BTUH to heat a house you had availible 25-30,000 BTUH for some of the domestic hot water heating needs when heat was required.

When heat was not required you had the whole 100,000 BTUH avalible for domestic hot water.

Today people use hot water as if it would never run out. Many of our customers use several bath rooms at the same time as well as washing machiens. In many instances the draw could reach 6 gpm, that is 300,000 BTUH. If we had to size a boiler for steam heating we would have to add another 200,000 BTUH to boiler size.

Can you imagine how many jobs would be lost on boiler change outs if we installed a boiler that is three times larger than what the building needs.

The same goes for hot water boilers.

I personly prefer a coil in a boiler especialy if it is a steam boiler. I donot like to see a steam boiler sit idle for half a year (other conditions & maintenance).

Forget every thing about what AGA says because the more gas appliances that you install gives them a reason for being.

It is all about what the customer needs, Giving them the best bang for the buck and providing the needed services.

Water conditions, space availible, and fuel econmy is what shpuld drive our industry.

If a customer want a coil in the boiler explain to them the pros and cons if the still want the coil in the boiler and are willing to pay for it give it to them.

No one has ever been able to prove that in long term you save money by installing eigther system.

Jake

Dan Foley1

Burnham

Burnham makes a gas boiler, the Independence, that is rated for hot water or steam and is available with an optional tankless coil. -DF