Our house has a 75000 BTU direct vent condensing natural gas furnace. This
is our first winter here but the house and furnace are 8 years old.
We've had some real cold weather lately, below zero around the clock for
over a week. The furnace is running alot, however I've woke up in the
morning a couple of times to find the house pretty cold and the furnace not
running. The vent blower is on, but nothing else. I figured that this
meant the furnace could not prove draft or exhaust. Went out side to find
the inlet pipe frosted over. Cleaned it off and the furnace runs.
I took out the manual to check the installation and wow the previous guy
really cut some corners. First the manual states that the centers of both
pipes are suppose to terminate a minimum of 8" apart( 18" min. in very cold
climates, sustained below zero), mine are barely 5". The pipes are supposed
to extend 8" from the building wall, mine are practically flush. The inlet
is sucking in the moist exhaust air and it is freezing on the screen. He
did use the right size pipes for the length of the runs and number of 90s.
Back to the good news, he runs the pipes to the back of the house and
underneath our deck, and the basement is finished with sheetrock so I have
no access to the pipes once they leave the furnace area.
Can I put a 90, pointing down on the inlet, and extend the exhaust pipe 18"?
This would give me my separation, however the terminations would not be the
same distance from the house.
Also will PVC primer and cement work in ten degree weather? I can make
everything up inside, but I'll need to do the final tie-ins outside.
Also there seems to be quite a bit of liquid running out of the exhaust
pipe, should I pitch it down some? I'm worried that this moisture will
freeze with the pipe 18" away from the house.
Finally is anyone responsible for a dangerous installation like this? I
know you purchase a house as is, however does an installer either
professional or homeowner accept a liability when installing these things?
Thanks for your time,