Nordyne R410 TXV failures

[JBocc]

I was in the local supplier today and I was asked if I had ever seen failures such as ruptured power heads and sensing bulbs that have blown off. He has a collection of returned txv's. I am not a Nordyne installer. Any insight??? Over pressure of volatile gas side but why??

[jtrammel]

We've sold a couple handfuls of broan and nutone units and haven't had any txv problems.

[JBocc]

These would be in Frigidaire heat pumps

[jtrammel]

That would be the same as a Broan, we installed probably 10 split heat pumps and 5 packaged heat pumps and 2 packaged duel fuels and haven't had any problems with txvs. We did have a compressor go out on one of the dual fuels, quality pledge gave us a complete new unit and some labor $ to install it.

[BaldLoonie]

The single stage heat pumps have pistons outside. That's about all we sell. Inside, they use Danfoss TXVs. Knock on wood but they seem to be more reliable than some of the other brands used on competing products.

[JBocc]

Indeed they are danfoss valves. I wonder if they are aware of this issue?

[craig1]

I've installed a lot of these systems and have never has a txv failure of any sort.

These coils have factory installed txvs. I wonder if installers are overheating the bulb when brazing the suction line, causing over pressurization. I only use staybrite and cool the joint immediately after soldering. This minimizes heat on the txv bulb.

[Spide]

there was a service bulletin (last year?) advising the superheat bulb be removed from suction line before brazing.

[JBocc]

good point on the brazing...I can only assume they are doing it correctly...but then again. I will pass on about the service bulletin info. Can you provide bulletin??

[beenthere]

I was in the local supplier today and I was asked if I had ever seen failures such as ruptured power heads and sensing bulbs that have blown off. He has a collection of returned txv's. I am not a Nordyne installer. Any insight??? Over pressure of volatile gas side but why??

Maybe the guys that installed those units over heated the bulb that much.