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  1. Which Pump for Flushing Tankless?

    I have a Rinnai RUR199en tankless water heater. For maintenance I need to flush it with vinegar about once/year using a bucket of vinegar, 3/4" connection hoses, and a submersible pump. Rinnai won't recommend a pump to use for this operation. They only recommend that it push just 4GPM. The...
  2. Navien vs Rinnai tankless water heaters

    We just installed a Navien NPE 180-A tankless water heater. It is installed outside our house between our two bathrooms. When we use hot water we can hear it starting up everytime. In researching I found that the Rinnai RUR98 is well-rated and is very quiet. Would we find it noticeably more...
  3. Rinnai (R94LS) Heating Issue

    Rinnai (R94LS) I have two faucets that are separate handles for hot and cold. Both of those draw hot water. But in the last two months my shower and kitchen sink faucet (which are single handle faucet mixer values do not draw hot water all the time. However, if I start the hot water off the hot...
  4. Rinnai RUC90i cuts out, error 12

    I'm at wits end and need some guidance on this one... Just replaced a 20 year old Aquastar propane tankless 180,000 btu/hr on demand water heater with a Rinnai RUC90i 180,000 btu/hr one. Old heater used indoor combustion air and had pilot, not much in the way of electronics, had...
  5. Rinnai RL94I Tankless Heater

    Hi, I just purchased a a home back in Jan-14 with a Rinnai RL94I installed, it has worked well until today. I received a code 11 and a code 6, which I believe are codes for no ignition and no flame. I tried un-plugging it, didn't think it was gonna work anyway but I had to try. I read on...
  6. Drill hole in conentric vent for tankless water heater?

    I have a recently installed Rinnai RU801 Tankless Water Heater. The WH was installed with the concentric vent option. The WH is mounted on an interior wall, and the vent goes directly to a 90 degree elbow, then slopes UP to the exterior wall over about a 10 foot distance, then 90s up, second 90...
  7. Tankless Water Heater with Recirculation Diagram

    I live in New York state and had a Rinnai RU80i tankless water heater installed in the basement of my house. I am doing the plumbing for the cold and hot water pipes and wanted to get some feedback on if I designed the system correctly (a diagram is attached--larger PDF too). There are fixtures...
  8. Tankless H2O Gas Ventilation

    I read in Don Geary's article on that Rinnai indoor gas heaters cannot be exhaust vented into another appliance's exhaust pipes since the Rinnai has a forced air exhaust, and presumably it would backflow fumes out of the other appliance (furnace, etc..). I am looking to...