True Blue

Old 01-02-10, 01:39 PM
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True Blue

I have a tech 4 true blue 90 im not sure what the problem is but it has to do with pressure switch. when i turn on thermostat nothing happens but if i go and open heater pull the 1/4 hose off the the 2" pvc going outside and give the hose a little suction the fan comes on and after 30 seconds the furnace lights and works fine the other end of the 1/4 hose goes to the pressure switch. can anyone help me with this its a strait temp of -4 in north WI
Old 01-02-10, 02:10 PM
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Pressure Switch

Check the exhaust & intake (if two pvc pipes outside) to make sure neither is blocked. Is there a steady plume of steam coming out of the exhaust while the furnace is running?
Old 01-02-10, 06:19 PM
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You may be getting water in that tube and it won't let that switch open after a heat cycle.

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