Replace Chimney Lining with new Burner/Boiler
Under what circumstances will I have to have my chimney relined if I upgrade my heating system.
I have seen gas heaters that bypass the chimney completely, and just vent through PVC pipes coming out the side of the house. Is this an option for me?
What should be the approx total cost of converting from oil to gas heat?
Re: Replace Chimney Lining with new Burner/Boiler
The decision to use a chimney liner is left to the discretion of the licensed installer, and would depend on the type of heating unit installed.
Aside from the case of installing a very high efficiency condensing boiler or furnace (where just a plastic vent pipe & plastic drain is required), the decision would be based on whether the present masonry (brick) chimney would be able to heat up sufficiently to pass the stack exhaust gases up & out of the house.
Older boilers/furnaces (and replacement low-cost cast iron units) produce a high stack temp of approx. 600 degrees which is sufficient to heat the inner walls of the brick chimney to create an exhaust lift so the poisonous gases can go up the chimney---this high temp wastes a lot of fuel.
The newer more efficient heating packages produce a stack exhaust gas of approx. 300 degrees or less; this is often insufficient to heat the chimney innards & a metal liner must be installed so the gas will lift out of the house; gas-fired units require an aluminum liner for approx $300 plus install.; oil-fired units require a stainless steel liner for approx $900 plus install.
The total cost of converting from oil to gas would depend on which new boiler you choose to buy; you could buy a standard cast iron gas boiler for approx. $2k plus install that wouldn't need a liner (but would have a fuel efficiency of only 83%); or you could buy a triple pass boiler at 87% AFUE at $3k or $4k (that may need a liner, plus install.), or you could buy a stainless steel condensing boiler at approx. 95% AFUE efficiency w/plas. vent/drain plus install. for $6k to $8k.
There are usually energy star rebates available in various states for having the higher efficiency equipment installed, in the interest of reducing fossil fuel consumption.
These price quotes are approximate & it is imperative that you get at least 3-4 estimates with different brands & styles before you buy.