Rinnai Direct Vent Propane heater

[Burrcreek]

Using a Rinnai EX38CT (RHFE-1005-FTA2) for approx 6 years and looking for info from other experienced users or techs.
1. Internet searches suggest this model is now discontinued. True? Why?
2. My unit cycles more frequently than I would like. Attached themostat sensor cord is too short to significantly relocate. I don’t want to purchase a wall mount thermostat. Wonder if others have issues with frequent cycling and whether there’s a way to get or make a longer cord?
3. Combustion fan was replaced 2 years ago and is now making a high pitched sound during its cycle. I am going to replace it again but wondering if others have similar issues? Also, maybe the very frequent recycling is shortening the lifespan of the combustion fan?

Thx in advance for any useful help.

 

[The Cobbler]

No idea why a company would discontinue, but it happens all the time to bring out a similar "upgraded " model.
looked online and one of their claims is keeping a very close set temperature in the room. if you don't want that probably and you don;t want to buy another thermostat, probably have to just live with it. I doubt the frequent cycling is causing your fan motor issues .

 

[nadogail]

Many times existing and previously popular models are upgraded to include new features or gain competitive advantage.
Even though you may have enjoyed owning your first car, would you still be interested in it if the available replacement was not different from its predecessor?

 

[Bert_]

Even though you may have enjoyed owning your first car, would you still be interested in it if the available replacement was not different from its predecessor?

Side track,

I wish this was an option! I am forced to buy old junk because they don't make it anymore!

 

[fitter30]

Here's a service manual. Page 80 show sensor vary resistance. Burn lp? If fan is quite before burner fires then after it fires could be burner set up or dirty. Manual goes into it.

https://www.google.com/url?q=https://media.rinnai.us/salsify_asset/s-3406a2d0-e0f0-4876-9f26-95943260d2a1/200000014%2520Direct%2520Vent%2520Service%2520Manual.pdf&sa=U&ved=2ahUKEwjbyZqY-_CKAxWtMdAFHW3VOnIQFnoECA4QAg&usg=AOvVaw1Xgqwu8N2I5Tf0O2jFz7B-

 

[Jackfre]

The Current model is the EX38DT. I have been gone from the company for six yrs now and am not aware of the control changes on D model. I suspect it only a control mod as otherwise they would change the model number. Over the years it has gone from a 1001 to 1004 and your current 1005. I regularly have relocated the stat bulb on mine. At 2“ off the floor the stat bulb get the coldest air in the space. That is fine unless you have some leakage taht puts direct cold air on it at which point it will run hard. It is simple to get the cover off the unit. The extra stat wire is coiled up inside. Sometimes I will pull it up and wire tie it to the gas line area or tick the bulb through the air louvers on the side and tie it off there just protruding from the louver. That gets it out into the room air a bit better. That units modulates from 13,200-38,000 on NG. How big is this space the heater is in? At its 80% you are netting 10,600 btu to the space. If it is oversized, poor air distribution within the space or the stat seeing infiltration at the floor it will respond to it input and cycle.
I am concerned that the unit is making noise. Frequent replacement of motors/fans on Rinnai’s is uncommon in the extreme. I based that on 30yrs with the company.
is this in your shop or home? While you have the cover off the unit for the stat re-locate, check out the room air fans, If they are loaded up get a bottle brush and compressed air to clean them. You might also check the venting on the unit. Is there a restriction in the vent or the air supply flexible tube from the vent to the unit? Any restrictions there would potentially cause short cycling or noise. I installed the first 1005 in the US in my shop in about ‘15. If you need it, Rinnai‘s Tech Service is very good. 1 800 621-9419. Post a picture of the install. I may be able to pick something up. Happy Heating!

 

[Burrcreek]

Here's a service manual. Page 80 show sensor vary resistance. Burn lp? If fan is quite before burner fires then after it fires could be burner set up or dirty. Manual goes into it.

https://www.google.com/url?q=https://media.rinnai.us/salsify_asset/s-3406a2d0-e0f0-4876-9f26-95943260d2a1/200000014%2520Direct%2520Vent%2520Service%2520Manual.pdf&sa=U&ved=2ahUKEwjbyZqY-_CKAxWtMdAFHW3VOnIQFnoECA4QAg&usg=AOvVaw1Xgqwu8N2I5Tf0O2jFz7B-

Thx.

 

[Burrcreek]

The Current model is the EX38DT. I have been gone from the company for six yrs now and am not aware of the control changes on D model. I suspect it only a control mod as otherwise they would change the model number. Over the years it has gone from a 1001 to 1004 and your current 1005. I regularly have relocated the stat bulb on mine. At 2“ off the floor the stat bulb get the coldest air in the space. That is fine unless you have some leakage taht puts direct cold air on it at which point it will run hard. It is simple to get the cover off the unit. The extra stat wire is coiled up inside. Sometimes I will pull it up and wire tie it to the gas line area or tick the bulb through the air louvers on the side and tie it off there just protruding from the louver. That gets it out into the room air a bit better. That units modulates from 13,200-38,000 on NG. How big is this space the heater is in? At its 80% you are netting 10,600 btu to the space. If it is oversized, poor air distribution within the space or the stat seeing infiltration at the floor it will respond to it input and cycle.
I am concerned that the unit is making noise. Frequent replacement of motors/fans on Rinnai’s is uncommon in the extreme. I based that on 30yrs with the company.
is this in your shop or home? While you have the cover off the unit for the stat re-locate, check out the room air fans, If they are loaded up get a bottle brush and compressed air to clean them. You might also check the venting on the unit. Is there a restriction in the vent or the air supply flexible tube from the vent to the unit? Any restrictions there would potentially cause short cycling or noise. I installed the first 1005 in the US in my shop in about ‘15. If you need it, Rinnai‘s Tech Service is very good. 1 800 621-9419. Post a picture of the install. I may be able to pick something up. Happy Heating!

Thx. Appreciate the thorough response. Unit is installed in home and has worked well for 6 years other than frequent cycling and combustion fan issues. RE the cycling, I wish Rinnai would program in an option for constant “low, medium, high” settings and/or a setting allowing for less temp sensitivity and wider on/off range. Otherwise, I pretty much know and have done/tried everything mentioned. Successfully replaced the fan yesterday so we’ll see how it works. Rinnai Tech won’t give out any info to anyone who is not a licensed tech. Probably a liability thing but not at all helpful for remote real world situations where techs are few and far between.

 

[Jackfre]

When sized properly they do not cycle. On any modulating equipment the low fire is actually more important than the high fire. One thing I was disappointed in with the 1005 vs the 1004 was the increase in low fire from what had been 10,500 up to the 13,200.Doesn’t seem like much, but on the margins it does matter. I had an EX-22 in my MA home that at a minimum of 8200 btu would run all winter cycling off only on the odd days where it would hit 70* outside.. The space would handle the input. It appears that the unit is simply too large for the space. At this point I think you need to increase the space the unit is handling. Perhaps you could try a fan or two to other parts of the space to see if it settles the unit down. Also, maybe an in-line fan like a Fan-tech could be piped either thru the attic (best in this situation) or basement to move heat to a remote location in the home. Prior to buying a Fantech a couple floor fans to adjoining spaces would be good. I solved a lot of these types of problems adding high and low registers into adjoining spaces. Heat wants to go to cold areas. those registers worked and were minimum expense. We also used a lot of Tjernlund Airshares to get heat to adjoining areas. I did that on Rinnai’s as well as the Fujitsu mini-splits I also represented. Where are you and how big is the space the unit is heating. Is there any leakage throug hthe vent where it meets the wall? If the unit right next to a glass door. It only responds to temp difference and is very accurate in that respect.

 

[Burrcreek]

Thanks. I‘ll consider my options. (Starting to feel like the heater is controlling me more than I am controlling it. Haha.)