Monitor venting connections compatible with Rinnai?

[Maddog]

Hi, Our old monitor 41 has given up the ghost (really dead - long story) and it is being replaced with a Rinnai propane heater (ES38\1004). Our particular setup requires a 6ft extension and one additional corner to turn (2 bends total), I want to avoid having to get the full Rinnai extension kit. The venting (air intake\exhaust) looks very similar between the two units, does anyone know if the Monitor venting can be used by the Rinnai?Thanks,

[hawkins111]

proper flue pipe

Since the new heater is a gas unit I would not use any parts except those meant for the Rinnai. It is very important to use the correct flue pieces for a gas unit. You never want an exhaust leak, particularly with a gas unit. If you don’t want to buy the extension kit I would find a way to use the normal flue pipe. The extension kit might cause you trouble in the future with ice build up on the tip. The gas cools as it travels further. When it reaches the tip there is a chance of condensation, which will ice up the exhaust. Save yourself the trouble and use the standard flue. Tom

[Maddog]

Monitor\ Rinnai venting compatibility

Thx Hakwins111. We don't have a choice where the heater goes unfortunately due to the layout of the house. The new Rinnai unit will go in the same place as the old Monitor unit which already has the 6' flue extension in place for the Monitor. I was just hoping to connect the new unit to the venting already in place and to hear from someone that has successfully done this (who is still alive and not dead from CO2). What you say makes sense on the differences between kero\gas i.e. possible leaks and different air flow rates and convinces me that I should stick with accessories provided by the same company. Thanks,

[dfitz3390]

i would take Hawkins advice, i have done it but it will mean you have to make your own adapter to connect the exhaust . Not for the average handyman to be playing with for the obvious reasons.

[dfitz3390]

Maddog, are you installing the rinnai or are you having a service company install it ?

[Maddog]

Monitor \ Rinai venting connections

Hi dfitz3390, yes I was planning on installing the unit myself. I am pretty mechanically inclined and have installed a couple gas appliances before at other places (water heater & cookstove) so I didn't figure it would be much different, but not anything that required venting. I can do leak tests and know to use gas-compatible pipe dope but I wasn't figuring on doing a pressure test with only the heater to be drawing from the tank at the moment.

[dfitz3390]

The installation instructions usually come with the unit and the rinnai exhaust is better suited for your length and elbows. you are using the rinnai vent termination kit correct ?

[Maddog]

Monitor \ Rinai venting connections

Yes I plan to use the new assemby that includes the outside venting cover, pipe thru the wall, and consolidator at the inside end that all come with the Rinnai. Then the original Monitor exhaust and air tubes would hook up hopefully at each end without any major hassle.Thanks,

[hawkins111]

Rinnai flue pipe

Maddog, When you first posted about your Monitor 41 you did not mention the 6 foot exhaust extension. Now that we know about that extension the symptoms you stated all point to a blocked or partially blocked exhaust. Carbon build up, fuel build up in the pot, flame in the pot after it should have been burned off. I believe your exhaust pipes are sooted up. Again I will state, you should not use the Monitor exhaust pipes on the Rinnai. A gas stove is nothing to mess around with. Improper exhaust or air pipes can be dangerous. Be advised that Rinnai heaters do have a service bulletin issued by Rinnai that deals with a gasket that can break and should be replaced as per the manufactures instructions. Use the Rinnai web site and check the recalls. Tom

[dfitz3390]

Maddog - In addition to the the info Hawkins provided, the Rinnai extension pipes are considerably larger diameter than the Monitor pipes. I dont believe you will be able to connect the exhaust properly due to the size difference. I know it cost a bit more but safety and installing the unit (especially the venting) per manufactures instructions should be observed.

[Maddog]

Monitor \ Rinai venting connections

Thanks again Hawkins and Dfitz. Based on all the advice I will get the Rinnai extension kit and add'l elbow, better safe than sorry.On the original Monitor 41 issues, it could have been a parallel problem with the blocked venting early on, but the final diagnosis was a bad m/b contolling the fuel - it would simply not shut off (did bypass test) and was providing way too much fuel. It was completely rebuilt (burn chamber, flame ring, ignitor, flame rod, etc.), and the corroded burn chamber and almost nonexistent flame ring (after 25+ years use) were thought to be the culprit at first. Burn mat was all tiny scraps also. Exhaust and air intake were completely blown out w/a compressor, lots of black soot did come out of the exhaust. When it was all put back together however, same issue - incomplete burning of fuel causing it to get the error code 12 because of the burn run-on. Only after an inadvertent but maybe lucky error of the repair guy putting on the ignitor cover gasket over the wire leads (instead of under) causing a gap, did it become apparent that the burn chamber was becoming flooded with fuel because it was leaking out around the ignitor cover. The rate of fuel supply & consumption would almost catch up at high burn, but at anything below high burn the fuel would start to accumulate rapidly and come out the ignitor gasket. I gave up on the Monitor at that point on further gambles on getting it to work again, but it kind of worked out because the repair guy felt bad I guess and bought back all the repair parts and I was only out the cost for his time in the end.Thanks,