A Pulse 21 Lennox Furnace installed for $2900. with duckwork in 1992 has cost us $871. in service calls and warranty parts and parts that weren"t under warranty.We have had 7 service calls since 4/02 to 11/04 to b told the outside gas regulators were faulty.Are we liable for last 2 calls which total $269.50? $83.00 of his bill was for an inside gas valve part(28g14). This furnace was nothing but problems from the beginning.We have had 3 wall thermostats on it, they thought that was the problem. We never could go away 1 week-end and trust it.I have kept al the repairs bills and they total 11 to date. We feel that we are charged for a service call and the problem is not resolved within 30 days we should not have to pay for another service call. Whats your opinion. Thanks Bettie Hecker