Maker Pro
Maker Pro

Fujitsu Heat pump

I came across this site on my continuing saga with a Fujitsu heat pump (ASU15RLQ). It began with a storm, power outage, surge that blew the fuse in the outside unit. After replacing that, further investigation showed a blown fuse and varistor on the inside control board. Since the unit was still under warranty, I contacted the installer for repair. I was more than stunned to find out it would cost $1,000 to repair the unit. Labor isn't covered.

I searched google looking for a replacement tnr10v271K varistor and could only find it available in lots of 1,000 from China. I contacted a local distributor who would not deal with me as I wasn't a licensed HVAC person. I contacted Fujitsu service asking if I could get the part from them. They replied it was covered under warranty but they could not send it to me. Some warranty.

With my very limited electronics background, I looked at the data sheet for the tnr 10v271k and plugged the info into a online parts finder. It came up with a littlefuse v175la5p. So I order a few of those from arrow electronics.

After installing the new varistor and fuse I put it all back together. When I turned on the circuit breaker I heard a pop. Taking it apart again, I see that the replacement varistor burned up.

This leaves me wondering if my ignorance led me to choose a unacceptable replacement part. I would greatly appreciate someone looking at the following data sheets and let me know what they think.

http://www.datasheetdir.com/TNR10V271K+download original part
http://www.alldatasheet.com/datasheet-pdf/pdf/122789/LITTELFUSE/V175LA5P.html

The great resources listed in the faq led me to this potential replacement.

http://www.bourns.com/data/global/pdfs/MOV10D.pdf

Thanks for the help.
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Look for the specs of the device then find an equivalent part. (tick)

Then consider the risk/benefit of replacing it yourself.

There are several risks:

1) you will void your warranty.

2) there may be something else wrong.

if (1) and (2) then you are in a bad place.

However if you have some sort of consumer affairs to complain to, I would. $1000 for labour is way over the top.

A blown MOV (open circuit) would not stop the unit from functioning (but it does mean there's no protection against power surges). If it runs after the replacement of the fuse, go ahead and replace the MOV. If it doesn't, replacing the MOV isn't going to fix it.
 
Last edited:
Top