Heat loss from hot water tank vent?

[jons999]

In my house the hot water tank is located in a hallway off the kitchen. Its right out in the open, not in a closet or laundry room. The house seems to be very hard to keep warm despite being pretty well insulated. I'm just wondering how much heat i may be losing from the draft up the chimney of the hot water tank? I'm renting the house right now, if i buy it i will install a tankless heater in a utility closet but in the mean time is there any way to reduce heat loss without too many changes to the house, or is the chimney draft really not an issue?

Thanks,
Jon

[akaothermick]

In the old days they used to sell bi-metal thermal dampers for that problem, but they presented another carbon monoxide problem when they failed so they are no longer code and most were removed when a new tank was installed, a tank less unit still requires a vent but it is normally a power vent that still is an opening without any dampening, the heat loss is not that great, even less if it is located in a colder part of the house normally not occupied, like a basement, sometimes in warmer climates a unvented tank less is located on an exterior wall and uses a electric backup heater to prevent the occasional freezing temperatures from doing damage. Any gas fired appliance will require combustion air so sealing it in a closet will just cause problems such as intermittent shutdowns and such.

[HayZee518]

the bonnet on top of the heater combines room air with the combustion gases that go up the chimney. it forms a draft. some room air along with heat goes up the chimney. yes, could be a problem, but without that draft the gases would become a hazard to people in the house. like the above posting you could use an induced draft fan in the exhaust ductwork and the fan may reduce the amount of room air going up when it shuts down but you'll never eliminate it.