Help??!!

[gandm]

have a new carrier 7.5 ton hp system that had a restriction removed llsv & dryer cleared system with nitro, changed guts in llsv added new dryer, vacuumed system, charged system and started. runs good in cool mode but in heat mode suction pressure jumps to 120 psi indoor fan is running. Checked system throughly, indoor unit is a 40rmq, do not see any obivious problems,maybe did not let system run long enough? head pressure at 170psi, any ideas?:confused:

[hicks]

Sorry I have to ask. Did you have your suction hose at the service valve or at the reversing valve. If you were still at the service valve you would have high pressure due to the hot gas pumping thru the suction line in the heat mode?

[Hrdworkingacguy]

do you have a bad check valve? Might be a different unit I had trouble with, but the symptom is the same...:eek:

[plee]

I would have asked the same question about which port or you connected to.?
Have you checked to see if the reversing valve is working? Maybe you could feel the temp differences on the lines coming off the rev.. valve to be sure?

[supertek65]

Sorry I have to ask. Did you have your suction hose at the service valve or at the reversing valve. If you were still at the service valve you would have high pressure due to the hot gas pumping thru the suction line in the heat mode?

hopefully the discharge pressure is higher than 120!:D

[supertek65]

high suction, low head.
if it was a regular old air conditioner you would think bad valves. bad txv.
of course it runs well in cooling.
how about a bad check valve ?
is your reversing valve seating all the way?
is there a restriction in your pilot line keeping hot gas from holding the reversing valve all the way closed?
most likely the outdoor metering devise is stuck open if it is txv or orifice is too big if it is piston.
or check valve.
sounds like you are flooding the out door coil ie evaporator.