Thread: new HVAC techs among us

Originally Posted by Thom Walker

David R,

Are you saying I should not call for an HVAC evaluation of the system if I see one of these? My logic was that this is an advertised "cheapest fix" solution to one of two possible causes for coil freeze up. My concern is that when this is installed the blower motor is still too small and or the ducts are still in need of repair. Their own advertising leads me to think this should have been called THE MASK.

I'm glad you HVAC guys are here. You've really upped the level of quality information.

Thom,

If the stat is being used as a "band aid" for a more in depth problem then it needs to be investigated absolutely. If it is being used as a safety I see no need in further investigation.
The problem arises trying to figure out why it was installed, many times I have seen them on some equipment straight out of the factory.
More than likely if it is installed in a lock out circuit you can bet it was for safety.
If there are existing issues the continued lock outs would drive you crazy from nuisance callbacks.

It is odd you mention an undersized blower just found one last week that was running a 24º delta T.
Equipment was installed new as a mismatch 2 ton water source heat pump on an air handler only capable of moving 600 CFM of air.

Did I mention this install was 14 years old & was having yearly maintenance performed on it by the installing contractor.

One more question; if the installation of the stat was part of the original installation, could it then mask future problems with conditioned air loss that might otherwise have been discovered? From your post, it is appears that it did a good job of hiding the undersized blower in that 14 years old system.

Sorry for the confusion on bringing up that scenario, no freezestat was installed in that air handler.

If there had been one installed with a lock out circuit it would have been locking out consistently on a nuisance basis from day one.

Might have been bypassed due to the freezestat being "faulty" if there had been one installed.

Originally Posted by DavidR

This situation is not possible unless the float switch were to fail closed, if the primary is clogged the secondary float switch kills the outside unit.

"if the primary is clogged the secondary float switch kills the outside unit", correct - and that is when the ice melts.

No compressor running, no freeze up.

'Cept that the coil ALREADY froze up - BEFORE the compressor shut off, and when the ice melts, that water goes ... downhill.

DavidR,

Thanks for the info on the Freezestat.

Wonder if ... (I'll have to use that on new construction when they do not want to install the auxiliary drain pan and drain line to it, of course, though, 'only after applying the manufacturer's installation instructions first' ).

Here's a question:

Is it allowed for an HI to recommend an HVAC specialist from/on this site? I'm reading these posts, and the knowledge that spills forth from some of these posts is incredible (to me, at least)

Let me know guys if this is something I should or should not do.... more business for the hvac contractor, and more happy clients for both of us in the "takin' care of business" category.

Bob

Originally Posted by Jerry Peck

"if the primary is clogged the secondary float switch kills the outside unit", correct - and that is when the ice melts.



'Cept that the coil ALREADY froze up - BEFORE the compressor shut off, and when the ice melts, that water goes ... downhill.

Oh now you're just being silly Jerry.

In all seriousness you bring up a valid point here that could be a possibility.

I am going to look into the float switch being placed on the primary above the trap then piping the secondary to auxiliary drain.

I really like that mineral oil idea.

DavidR,

Glad we could help.

Actually, thank you for your help and information.