To avert this problem you can vent the water heater to the largest hole in the chimney and cap the remaining holes.
Can i vent my gas water heater through the wall.
Also you need to be aware of combustion air intake requirements for any type of heater.
Tankless water heaters provide either horizontal venting or vertical venting which is also referred to as tankless water heater venting through roof.
Direct vent chimneys fireplaces.
Yes you can vent a gas fired water heater out of the wall if it is either a power vent unit.
A power vent water heater will cost about the same as a tankless heater and avoiding a through the roof vent can make the difference in a tankless installation being affordable or not.
Venting a garage heater through a wall the other solution to ventilating your garage when installing a gas heater is to run the vent duct through the wall of your garage.
This will allow your water heater to operate efficiently and effectively and most significantly it will avoid any probability of danger and therefore the risk of carbon monoxide gas poisoning.
Sidewall vent direct vent direct exhaust systems for oil or gas fired heaters.
They do make two models of power vent units one is called a direct vent power vent as bob harper pointed out it draws its combustion air from outside unlike a standard power vent unit which burns its combustion air from the dwelling.
Other issue is the bathroom installation which isn t permitted as well unless the water heater closet is sealed from the bathroom area air tight doors and it has a separate fresh air supply from exterior or other areas of the house that can be used for this purpose.
When venting a gas water heater to a chimney be aware that holes in the chimney can prevent a good draw on the water heater causing downdrafts and presenting the risk of carbon monoxide poisoning.
Direct vent water heaters.
Illustrations of proper gas fired water heater venting using type b double wall vent pipe through a roof above or through a chimney below include details for the flue vent connector such as the requirement of a minimum vent connector upwards slope of 1 4 per foot of horizontal run.
With a direct vent system air for combustion is drawn from a vent pipe that runs through an exterior wall or the roof.
Then just secure the 90 degree elbow to the flange on the heater by using 1 self tapping screws along the rim of the elbow.
Exhaust gases are vented outdoors through a separate vent duct or through a separate chamber of the same pipe this requires a double wall vent duct.