First, does anyone know if I can replace a compresser motor start capacitor that has failed with one that has a slightly higher MFD rating? The one I took out is rated at 176-211MFD 330Vac and has a 150 Ohm resistor across the terminals. The only one I could find that was close was rated at 189-227MFD 330Vac. I also found one that was rated at 161-193MFD 330Vac. Can I use the 189-227MFD cap with a 150 Ohm resistor, or does the resistance have to change slightly?

I am currently doing battle with this ten year old WaterFurnace brand open loop system. It has not worked correctly since the day it was installed by the "qualified and licensed" professionals from a local pumbing company that charged way too much for poor quality work. Initially, the two-story 3,000 sqft house with a finished basement was All on one zone. Then the contractor separated the first and second floors and put a thermostat to control the second floor in a room where there were no registers. The stages have never been set right and it always goes into emergency heat mode whenever a thermostat calls for heat. It has also suffered multiple voltage surges--one from a lighting strike and the others from the power company.

In May I came home from college to my parents house and found that the 100 amp backup electric heater had been on for two months straight 24/7 without the blower fan running. I turned off all power to the unit until I could find out what was wrong with it. I opened the furnace and found that the start capacitor for the compresser had exploded and shorted against the metal enclosure of the furnace. I am very hesitant to call the company that initially installed this unit because they have failed to show me that they know anything about it. They are a reputable company in the area installing standard NG and LP units, however they messed up every aspect of this progect including the ducting supply and returns, well pump size requirements for the furnace, zoning and thermostat control.

Any help in this matter would be greatly appreaciated since the days are getting cooler and this furnace has not worked since May.

Adam

 

I take it that this is a Old Reliable start cap you have . Id say yes go for the 189-227 MFD at 330. that will kick the motor there for sure . I think you will find that the resistor there is 2W 15000 they are just there to act as a bleeder on the cap is all. if the one you have is good take it off and put it on the new cap is all.

Not sure what you have there . If is a well to well heat pump could be you have to clean out the coils they get limed up.
Is this all fixed now and running. That could have been lighting Glad the oil didnt get on fire there.

ED

 

The heat pump draws from our domestic water well and then daylights it out on the surface a few yards away from the well (open-loop system). Haven't had a problem with lime yet.

The old cap is an Areo M (made by areovox?). I tried looking around on-line, but couldn't find one to match exactly. I'll try using the 189-227MFD with the larger bleed resistor, just wanted to get another's opinion on the subject.

Thanks,

Adam

 

Keep an eye on the head psi there . I learned a longtime ago if a AC or heatpump has anything to do with water you have to keep the heat exchanger coils cleaned out all the time.

ED