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-   -   Lennox service valve questions (http://www.diychatroom.com/f17/lennox-service-valve-questions-49448/)

leeh1212 07-22-2009 10:51 PM

Lennox service valve questions
 
When the service technician checks and charges my Lennox unit, should he have to open the service valve or can he do everything by hooking up to the schrader and not messing with the service valve at all.

The reason I ask is that I had a maintenance checkup and the technician said I was several ibs low on refrigerant and so I had to authorize a service call. The next guy came out and said the unit was fully charged but all he did was hookup gauges to the schrader valves and never removed the caps on the service valves.

My unit still cools poorly so he said it must be the age of the unit which is now 11 years. I was upset I had to pay for the service call recommended by the tuneup guy, which resulted in no additional service. That is why I wondered if the service guy knew what he was doing since I asked to see when he said there was no problem.

Thx

hvaclover 07-22-2009 10:56 PM

Interesting. An open service valve and a schrader. How did you become to well versed in hvac terminology?

leeh1212 07-23-2009 08:07 AM

Hi, I am an electrical engineer and curious by nature. I read the installation manual that came with my unit HS26-024-2P and then I did some research on the web. That is how I found DIY. I know about schrader valves because they are used on a lot of stuff. Everything I looked at talks about the service valve on the Lennox, but not on how it is specifically used. When I look at the drawings which reveal the insides of the valve, it looks as if the valve has to be open to allow the schrader access to the system, but I know the technician saw some pressure reading on the gauges (about 70 psig) so I just wanted to be sure. If I find out the service valve needs to be open, maybe I can get the service company to come out and recheck without having to pay another $100 on top of what i already paid.

Any insight would be appreciated.
Thx

SKIP4661 07-23-2009 01:57 PM

I can't speak for all companies, but it would seem like someone sent to do a tune up would be able add freon. It shouldn't require an additional service call. I would be a little leery of this company. Any company I ever worked for required the techs to add freon when necessary. There may be an additional charge for freon used.

biggles 07-23-2009 04:39 PM

the service valve are fully open to run the unit full CCW up on allen key...the unit will pump down low pressure or go off on high pressue if they are closed full CW down.the shradders are pressurized open or closed system on or off the first brain surgeon should of checked for leaks and added freon and do temp splits to check the charge.:whistling2:

KayJay 07-23-2009 10:47 PM

Many of the service valves I see have three positions. These valves are normally backseated as added protection against leaks through the gauge ports and valve stem packing. There would be no actual pressure reading from the gauge ports with the valves in this position.

leeh1212 07-24-2009 06:26 PM

Thanks for the info about the service valves. Since my AC is still not cooling even though the last technician said the system was charged, I guess I'll have to make another call to a different shop. Thanks again.:thumbup:

leeh1212 07-24-2009 06:35 PM

and to reply to Skip, the guy who did the checkup said he was only allowed to add up to 1 lb and he thought I needed 4. Looks like he may have been right afterall and the second technician was wrong since my AC is not cooling anymore.

I just ordered a set of gauges so I can check the pressure myself.

hvaclover 07-25-2009 12:20 AM

Quote:

Originally Posted by leeh1212 (Post 306295)
and to reply to Skip, the guy who did the checkup said he was only allowed to add up to 1 lb and he thought I needed 4. Looks like he may have been right afterall and the second technician was wrong since my AC is not cooling anymore.

I just ordered a set of gauges so I can check the pressure myself.

Better get an EPA card. Can't do a Diminimus purge with out it.

trader jac 07-25-2013 06:18 PM

Quote:

Originally Posted by biggles (Post 305879)
the service valve are fully open to run the unit full CCW up on allen key...the unit will pump down low pressure or go off on high pressue if they are closed full CW down.the shradders are pressurized open or closed system on or off the first brain surgeon should of checked for leaks and added freon and do temp splits to check the charge.:whistling2:

does the service tech turn the allen key fully ccw when he's done? do u do the same to backseat the valve? can u put packing material or o-ring in the dust cap to stop leaks? if left in its mid-seat position by the service tech after adding r22 will this cause the valve to leak more in the future?

biggles 07-25-2013 07:09 PM

the allen key'd service valves don't need to be touched at anytime except if the Freon is removed on a condenser change out.the shradders are like the ones on your car tire...2 service calls and the unit still isn't cooling...the unit is old is crap doesn't float complain to the service manager with a phone call.:wink:

beenthere 07-25-2013 10:42 PM

Wow, a 4 year old thread.

yuri 07-26-2013 08:59 AM

An Oldie but a Goodie.

There are 2 types of service valves. The old school steel body traditional type mostly used for refrigeration and the newer brass body type with built in schraeder valves. The old ones have NO Schraeder valve and therefore need to be manually opened and closed and the new ones have a schraeder valve. The old ones stopped being used 15 yrs ago and replaced by the new ones due to the cost factor. The new ones have a knife edge on the underside of the cap and body and that is what seals it, brass to brass seals well as they are soft metals.


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