Paloma error code c2 11 when wanting hot water

by Clayton
(Rock Springs, Wy, US)

I bought a new house in 2009 that has a Paloma Tankless Water Heater model #PTG-74PVN-2. It was working great but for a couple of months now I've been getting the c2 11 error when we want hot water.

The water heater doesn't do it all the time, which is odd, but we can leave the water and go downstairs to the heater and the digital reader is flashing the code c2 11.

We tried the whole waiting five minutes thing and sometimes it would work but not very often. The best thing we found is to leave the water on upstairs then go down and feather the hot water valve out of the heater and it takes awhile but it will eventually start the burner and everything will be fine. It's a pain in the ass though when it does it because of the hassle we have to go through just to get it hot again, and when we wash clothes or have the dishwasher running more than half the time I doubt it's actually warm!

There has to be something simple to fix it I would think. It almost acts like the sensor that sees the burner shuts it down way too soon because I can pull the cover off and see nothing wrong with the flame as it burns. It's just funny it doesn't do it all the time.

Does anyone know how to fix this water heater without telling me to make sure all the valves are open and simple things like that?

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Apr 05, 2021
C2 11 error code
by: Sharmaine Mons

Nearly every time the gas runs out we get this error message and sometimes for 3 days do not have hot water. This is becoming ridiculous.

May 18, 2020
c2 11
by: Anonymous

kill the power

disconnect the thermostat

cut the power back on

cut the water on, the water should heat up to around 120 degrees for about 30 seconds and then drop down to 102/104 degrees

if this is the case it is probably the thermostat
at least that's what fixed mine


Oct 07, 2011
Paloma troubleshooting
by: Liu

c2 11 error code on Paloma tankless water heater is for the ignition failure. What you should check, as long as you know what are you doing, are:

- Gas shutoff valve - it is not fully open... there is some obstruction, low gas pressure or air in the system.

- Check also the burner assembly. First you have to remove the cover. Build-up on the gas burner will restrict the gas flow. While doing the cleaning, clean the flame rod also. Make sure that the power is OFF.

- Solenoid valve or gas control valve

- Flame rod - clean

- Igniter - clean

Also recommendation is to check for any interruption in the venting system - dust, dirt... Insufficient air flow will prevent proper combustion.

This is what I would check... or call the licensed technician for Paloma tankless water heaters, not a plumber or electrician, but licensed professional.

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