Replacing my "vibrating Munchkin"

Michael_Pastrone

Hello again, Its nice to see most everyone is still here after ten years. I am back, exploring ideas on what to replace my Munchkin T80M with?



This HO has the proverbial "vibrating Munchkin" problem. And searches for that phrase here, and elsewhere, reveal how prevalent the problem may be. I appreciate the efforts made by folks here, at HTP, and the various competent P&H professionals who have attempted to address the problem. But after replacing or adjusting almost every part/pipe/flame (Blower six times) over ten years, I am convinced my T80M installation is not fixable.



To be fare, like a wind instrument any furnace will have resonate frequencies. Unfortunately, in my system those resonances destroy the Blower motor bearings every 18 months. Hopefully my T80M's replacement will have resonances outside its operating range or are more effectively dampened.



I am considering an HTP Elite FT.

It appears the wall hung (EFT-80) would plug in without much modification.



Very interested in your thoughts?

Zman

FT

The Elite ft  uses the firetube heat exchanger developed by Triangle Tube.

If you are getting good support from HTP, it sounds like a winner.

Lochinvar and Triangle tube make similar units.

As for the original munchkin, did anyone look into the possibility that the exhaust is getting sucked into the intake? What do the vents look like on the outside of the house? How close together are they? This cross contamination will tear up fans.

Carl

Michael_Pastrone

Vents separtated by four feet

Thanks for the feedback.

Yes, HTP has been very supportive.

I have seen references to "firetube heat exchanger" and will research it.



The vent spacing is checked every time the unit undergoes a Blower replacement. The exhaust is four feet above the intake, are on the side of the house. Usually there is a breeze and even when its still its hard to imagine any back flow.



The resonance only happens at certain fan speeds.

It sounds like a freight train when 20 feet away.

Michael_Pastrone

Here is a link to a video that documents the resonance...

(Assuming posting links works here) Here is a link to a video that documents the resonance: https://picasaweb.google.com/mpastrone/2013_12_31MunchkinResonance?authuser=0&authkey=Gv1sRgCJW_ptjJs5KfTQ&feat=directlink

Steve Whitbeck

FT

All that I install are fire tube boilers of the high efficient design.

The HTP Elite FT is a good design. I have installed a few and have had good results.

I have also installed the Triangle Tube and Lochinvar versions.

I use the brand that fits the application.

The needs for a certain control system or BTU output.

Michael_Pastrone

Added Video link

Added Video link