Water heater vs chimney liner options

[timr]

Hi,

We're in the process of upgrading an 80% eff oil furnance and oil fired hw heater to gas. We're going with a HE, direct vent furnace (which one is another topic :-) and have a few options I'd like some feedback on wrt to the water heater.

The chimney is brick, exterior and vintage - 50 years old, located in Ottawa Canada (cold winters). Chimney does show some signs of exterior brick flaking near the top. A 5" flex liner was installed about 15 years ago by the previous owner when the oil furnace was upgraded.

We're looking at installing a direct vent (non powered) water heater and sealing up the chimney but of course cost is an issue (~3x of installing a regular unit).

Some contractors have said the existing linker could be used with a regular water heater, others insist a new liner must be installed, while still others thought it would be difficult to install a new liner given the age of the chimney.

Questions:

- anyone have issues / problems with the direct vent water heaters?
- brands to avoid / recommend?

- any issues around venting a regular water heater up the existing 5" liner previously used for oil
(someone suggested the soot remaining from the oil gear may be a problem)

Thanks,
Tim

[perel]

I am only familiar with the CSIA system, don't know if there is something different used in Canada. If you have CSIA-trained sweeps as well, ask for a "Level 2" inspection. That involves putting a camera down the chimney - NOT just looking up it with a flashlight.