Combined Venting

ewhit2220

I have an Bradford white RG240S6N that I just purchased. I am also running a Peerless WBV-04-125-WPCT boiler that has hot water, but it is not working well. I got the hot water heater to convert just the domestic hot water.

I am wondering if I can vent both of those in the same chimney. The liner looks new, and it is about 20" around so that is about 6" diameter.

Any help would be greatly appreciated.

Larry Weingarten

Hi, What size vent does each appliance have, and what is the BTU input on each? That info will help👍

Yours, Larry

mattmia2

Is that boiler oil or gas?

EdTheHeaterMan

first of all, the barometric draft control on the boiler appears to be crooked. The face of the draft control must be installed plum, the hinge of the draft must be installed level. Unless your camera is at a really odd angle, it appears that your barometric draft control is not installed properly.

As far as installing a gas vented appliance like a water heater in the same chimney as an oil fired appliance, it is done all the time. It is important, however, to make sure that the 3” or 4” connector pipe from the water heater is at a point in the chimney that is higher than the oil burner Connector pipe. You do not want to connect the water heater under the flue connector of the Oil fired flue connector pipe.

See how this works on that liner connector Tee? Oil boiler at the bottom, gas water heater at the top.

Larry Weingarten brings up a good point about the BTU capacity of each burner. That will come from the boiler rating plate of the water heater and the boiler. A 6” liner can only vent so much exhaust. When you add those two BTU capacities together, it must not exceed the capacity of the 6 inch diameter, flue liner.

EBEBRATT-Ed

I doubt that will work. Your boiler flue is the same size as the liner. I doubt you can add any more capacity to that liner

ewhit2220

@Larry Weingarten The water heater has a 3 inch vent and 40,000 of BTU input. The boiler is 6 inches and has 175,000 BTU input.

@mattmia2 The boiler was just converted to gas by changing out the burner.

@EdTheHeaterMan Thanks for the comment, I just checked and it is not plum. I will adjust when installing. Does the fact that we converted to gas for the boiler change anything? And can you elaborate on why ordering the exhausts on the flue is important?

EdTheHeaterMan

If both appliances are gas, then there is no problem with the water heater entering as the same level or below the boiler. The reason for the gas water heater entering above the oil fired boiler has to do with the combustion byproducts of the oil fired boiler may leave solid particles that will accumulate at the base of the chimney. or the bottom of any horizontal vent connector. Those solids may build up and block the lower vent connector. if the water heater vent is blocked by that debris, then you will be venting exhaust gasses into your home.