Tankless heaters put out a lot of heat.
Can tankless water heater and furnace share vent.
A high e furnace has separate venting which leaves the existing vent pipe to serve only the water heater.
The furnace in the photos is a category i appliance a negative pressure draft vent appliance.
This unit is a condensing unit and requires a pvc vent so no you can t connect it to the common vent you describe.
Special stainless steel pipe.
A direct vent system pulls in.
Traditional gas tank water heater require venting through the roof.
Here are a few things your installer should consider for effective tankless water heater venting.
Before you decide against a tankless water heater for your next project consider these tankless water heater venting requirements.
Always follow the manufacturer s installation instructions exactly.
Vent to the outside.
Yes venting tankless water heater with furnace is possible.
Tankless water heaters can be vented in two ways.
If you were to tie the vents together the exhaust from the tankless water heater would be pushed through the furnace and into your indoor space.
The furnace is likely sized correctly with no room to add another appliance.
Tankless water heaters use fans to blow exhaust from the unit horizontally allowing vents to terminate on the side of a house.
The vent pipe must be made of stainless steel designed for venting corrosive gases.
However the key here is to install the vent pipe in the size required by the water heater.
Most homes have a shared vent serving both the furnace water heater when the furnace efficiency is up to 80 which is today s standard efficiency gas furnace.
This is because most homes have water heaters and furnace sharing the same exhaust vent.
You furnace vent pipe is probably type b vent and not suitable for this use.
Worst case scenario you kill your family.
Gas tankless water heaters don t have to use indoor air for combustion.
It would be a potential fire hazard.
Tankless water heaters can vent through the roof or a side wall creating more flexibility and options for placement.
Typically they require stainless steel triple wall venting.
The difference is that a power vent water heater pulls in combustion air from the space around the appliance then uses a fan to propel the exhaust through the vent.
Best case scenario you kill your furnace.
Facts about tankless water heater venting.
While there are high efficiency gas water heaters tank less units for one that utilize pvc for vents you will run into trouble trying to get the size correct for both.