Community Forums

DennisJM · 05-10-2015, 09:15 AM

Good Morning. Having Vibration issues with one of my heat pump/air conditioner unit. Can not run forward unit. Now middle unit starting to vibrate. Am up in Northern Minnesota at present with not much support. 2015 Phaeton. Any ideas.

garykk · 05-10-2015, 02:26 PM

Vibration is usually caused by loose bolts or the bolts tightened too tight and compressed the gasket....from what I have read, the unit should be sitting about 3/4" off the roof, if not, it may be tightened too much. Also check the fans etc for looseness...
A lot of us are switching from the factory installed 7 blade condenser fan to the newer 3 blade fan. Cuts down on noise and some vibration...there is a discussion about this over on the tiffinrv site.

luvlabs · 05-11-2015, 09:00 AM

The Mach A/C units have two fans that are powered independently. The condenser fan sits outdoors and just makes ennough noise to annoy you neighbors. The other fan is the evaporator fan and moves the inside air (its a squirrel cage fan).

You can easily test which one is making all the racket - turn the fan on via the thermostat (put the mode switch to off, and turn the fan on). If you are getting any noise other than air flowing through the ducts, shut the system down. Your evaporator fan has broken and needs to be replaced. Do not run the system.

If it makes noise in A/C or heat pump mode (you might hear it inside but especially outside) you might have a condensor fan (or fan blade) problem.

Call Tiffin Service, explain the problem, and they will authorize warranty payment for wherever you decide to take your MH. They will even pay for mobile repair if you want to go that route.

In the future, you might want to try tiffinrvnetwork.com. This is any owners site with far more Tiffin experts available to you.

DennisJM · 05-12-2015, 08:38 AM

Tiffin Service told me to take to Service Center in Minnesota, but can not get in until end of month. Was told my Tiffin Service I would have to pay for Mobile service, I will have to pay Mobile service, Can not go with out hot water for the remainder of Month. 100% electric coach.

garykk · 05-12-2015, 09:15 AM

How cold is it up there. These units will not run in the thirties. Make all sorts of noises..

traveler of california · 05-12-2015, 12:05 PM

My experience with Tiffin is they will not pay the service charge for a mobile service, but will pay the repair costs. Hell, mobile guys are usually less expensive than a shop.

ernieh · 05-12-2015, 02:22 PM

There are two major causes of "vibration" on the Mach 8 units.

One cause is an improperly installed unit. Sometimes the units are torqued down in such a way that the front of the unit contacts the roof. They say that this can be "adjusted" but I have heard of several who have inserted rubber door stops under the front to solve the problem.

The other common issue is the condenser fans. The original units had a 6 blade fan that worked great but was very noisy. The mfg. started using a 3 blade fan that was much quieter, but the early versions are prone to failure. If you have a 3 blade fan, you need to inspect it immediately, it may be cracking. The part number is on the top, and if the letter in the middle is a "B" or "C", it needs to be replaced with version "D". You can contact the mfg. directly for replacements. If they are cracked, they will replace under warranty. If not, the fans are around $20 and I my opinion should be replaced with the "D" versions anyway.

I have replaced several of these fans and have found several motor mounts that were not secure or broken. This issue needs to be addressed ASAP.