[JackDidley]

Title says it. 5 year old Rheem 2 ton. Cools well but when winter got here it only put out 83* air when it was 74* in the the house and 45* outside. Not a big deal, I just used my gas furnace all winter. I'd still like to get it fixed. The A coil does have an expansion valve built in. I will probably call in a pro but thought I could get some input here first. Thanks.
Cooling again now, it has an 18* drop coming out of the vents.

 

[roughneck]

What's the voltage to the reversing valve coil? Is the coil open?

 

[JackDidley]

Is that AC or DC ?

 

[user_12345a]

The reversing valve is fine in theory if it's heating when it's supposed to be heating and cooling when it's supposed to be cooling.

Check the delta-t in cooling mode - if u want to get further, check wetbulb return air temp. There are charts online that tell you what the supply temp should be at different wetbulbs, takes humidity into account.

With a normal split in cooling mode but poor performance in heating mode, you most likely have a a problem in the refrigeration circuit.

If you know that the airflow is right on (or know what the cfm is), you can use the delta-t to see how much heat the heatpump is providing.

Compare with manufacturer's data for a similar 2-ton.

Could be a heating metering device issue, check valve issue, something else.

 

[JackDidley]

Thanks. I dont recall the numbers but the airflow CFM was calculated at the time of install and matched to the unit. First 4 years, it heated well. Must be a metering or check valve issue.
Really not a big thing since I have a gas furnace also and I wont need it again for 6 months. Think I may call in a pro before they get real busy around here. It just sort of bugs me when things dont work.

 

[user_12345a]

Might be worth looking at the outdoor unit just to see if it's got a txv.

I suspect it's easier to troubleshoot a unit that's not working vs a unit that's working, but not well.

If the supply temp is good in cooling mode, it's not the charge.

I imagine a pro would have to check superheat in heating mode to verify that, not just reference a charging chart. (many things can cause low low side pressure) Would need low side pressure and line right upstream of the compressor.

You'll need a really skilled tech because I imagine an issue like this would be really hard to pin down.

 

[JackDidley]

OK. Thanks. Just looking for ideas. May not even be worth looking at. If it takes a few hours to find and fix, that adds up quick. Not to mention part$.

 

[bfletcher7]

May not even be worth looking at.

If he has a TXV metering device at the HP is it possible that---say---if its check valve is malfunctioning it could result in a cooling issue at some point in time?

 

[user_12345a]

If the check valve doesn't open and allow the refrigerant to bypass the heating metering device in cooling mode it will not cool right even with a perfect txv. (the valve may be built into the metering device, I wouldn't know)

I don't know how check valves can malfunction other than maybe stick or what else could be going on, the guys here with lots of experience would know.

Some refrigerant bypassing the metering device definitely would mess up performance.

Like I said b4 u would need a very good tech to sort this out.

It's good to have the option of running a heatpump, is worth fixing.

 

[user_12345a]

"Some refrigerant bypassing the metering device definitely would mess up performance."

...that is, refrig bypassing the meter device that's supposed to be active.


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Here's a good article i just found: http://www.achrnews.com/articles/82944-don-t-let-that-reversing-valve-outsmart-you