hah and Hubbard reversing valves failing

[cadwaladr]

Got one of these not shifting when energised give it a slight tap and shifts,this is on a GAH unit it's two years old another of my customers has had two replaced on warranty they were two Hubbard units anyone else had issues with them.

[charlie patt]

U will find the hot gas check valve spring week the one on the hot gas line or if it's blown a comp crap under the seat allows three way to chatter and wear cross saft out on three way

[cadwaladr]

no compressor change ever on this GAH its been cared for by me alone since birth never any issues,had a couple of drier changes and thats it it must just be a faulty valve,the lead time to get one from GAH is over a week comes as an assembly.by the way charlie your message box is full.

[Glenn Moore]

Hi cad
Do these units have a crankcase limit valve fitted ?

[cadwaladr]

Hi cad
Do these units have a crankcase limit valve fitted ?

I don't think so not the gah one that I am working on the Hubbard's I refer to have electric standby compressor and there is one fitted to them why ?

[Glenn Moore]

Hi cad
This sounds like an old problem with the Hubbard units. Some time back I was asked to look at the design of the units as often the reversing valve failed to operate. The units all had crankcase limit valves on. The Crankcase valve at certain conditions holds the suction pressure up to protect the compressor, and this can cause a low differential across the reversing valve which is not enough the force the piston over. So I cut the vent line on the reversing valve and reconnected it to the compressor side of the crankcase valve this increased the diff over the reversing valve and the valve worked ok . It means you have to mod the valve and lose the warranty .

[cadwaladr]

As I said no regulator I think but will check,you have to buy it from them as a made up kit,I am tempted just to buy the valve local my belief is it may have been damaged by heat during manufacture it's a gah by the way,don't fancy paying the price they want.

[cadwaladr]

Got this thing fixed believe it or not and remember this unit has been in use for two years,the problem has only arisen recently basically when the unit went on defrost the valve did not shift tap it slightly and it shifts,what I found was the magnetic coil was not on the plunger enough removed a screw which holds on if the small capillary tubes coil fits correctly and now operates the valve on demand,but how has it worked for 23 months?