Rinnai E110CRN Help

Cruisinfanatic

Had a problem with the unit starting up after a power failure the last few years. When the power is restored the unit just keeps making cycling noises and it begins to leak after some time. I found that if after power is restored and the heater is calling for heat, the unit will just make cycling noises and will never start to heat the house. I always managed to get it going but never knew what I did. Also when power is restored and there is a call for heat and it doesn't fire, it leaks from somewhere. Once this happenned when I was away for a couple days and didn't know. Just kept making noises all that time. And had a very wet floor. No leak when it's working right.

After years of troubleshooting I found that if all heat is off when power is restored, the unit would make those cycling noises for about 20-30 minutes then would stop. After the cycling (17 minute de-aeration cycle ) stopped, I could set the thermostats to call for heat and I'd be good.

Last year when researching, a tech suggested that the thermostat could be the issue. More research and found that the whole problem started when I replaced regular Honeywell programable with Honeywell RTH6580WF1001 Wi-Fi thermostats. More research and found that I basically used them right out of the box not adjusting any settings for my application. After adjusting the settings to my application all seemed well all last winter until now. After power outages the Rinnai started back up with no issue and never leaked.

A couple days ago that ended. Not sure if there was a power interruption or not, but no heat. Turned all thermosts off and then cut power for a few minutes and then turned back on, waited an hour with no call for heat. When I turned up heat, it didn't. This time there doesn't seem to be the 20 minutes of cycling as before. No heat.

Finally got a local master plumber here to look. He has tons of experience with Rinnai as well as others. He is a big guy and he didn't like the confined area it was in. Called it a poor instalation and didn't want much to do with it. He did call Rinnai and the resolution to get it going was to just manually open all of the zone valves. Then it fired. He believes the 9 yr old unit is ruined because of hard water even though I have a water softener and there is no evidence in the house of hard water. I've flushed it every 2 years as recommended and the vinegar circulating was always clean after.

He doesn't want to fix it, just replace it for $16,500 on the far end of a cold in the winter garage and a new softener for another $3500

Opinions on possible solutions appreciated

Pictures are during and after install

Peter49

Since manually opening the zone valves allowed the boiler to fire I'd check whether the circulation pump is actually getting sufficient flow during startup. The thermostat settings and zone valve end switches are worth checking as a failed valve or incorrect wiring could prevent proper circulation. I'd also have the leak source identified before agreeing to replace the boiler as the symptoms alone dont prove the heat exchanger has failed.