Gas Water Heater Problem: Solved

[rocky47]

We had been having problems with our gas water heater when camping above about 6000 ft ever since the trailer was new. The heater would start, the flame would blow out, the igniter would spark again (clicking noise) and sometimes re-ignite. Sometimes it would not start after 3 tries so we would have to turn the switch off and on to restart the process. It worked better with the heater door open, except when the wind was blowing, in which case having the door open blew out the flame immediately. I bought a digital manometer and adjusted the propane pressure—no help. I was finally able to talk to a Suburban tech who suggested de-rating the burner by installing a smaller orifice in order to make the propane/air ratio lower. This helped a bit but was not a complete solution. There was a forum thread back in 2018
https://www.escapeforum.org/forums/f...lem-12342.html
with a lot of good ideas but no definitive solutions. A couple of months ago I found this site
https://www.fulltimecaravanning.com.au/hot-water/
from a fellow in Australia who traced the issue to the igniter not being centered in the burner. My burner looked exactly like his “before” picture. I bent the rods so that they were centered, being careful to maintain the gap—this is a bit tricky since the rods are quite tough. If you do crack an insulator, however, a new igniter assembly is <$15 on Amazon. It worked, even after I reinstalled the larger orifice. We just completed 3 weeks camping up to 8300 ft with a water heater that worked flawlessly, and heated up more quickly since the burner is now operating at full output. YMMV

[oldwave]

Excellent

[rubicon327]

Originally Posted by rocky47

A couple of months ago I found this site
https://www.fulltimecaravanning.com.au/hot-water/
from a fellow in Australia who traced the issue to the igniter not being centered in the burner. My burner looked exactly like his “before” picture. I bent the rods so that they were centered, being careful to maintain the gap—this is a bit tricky since the rods are quite tough. If you do crack an insulator, however, a new igniter assembly is <$15 on Amazon. It worked, even after I reinstalled the larger orifice. We just completed 3 weeks camping up to 8300 ft with a water heater that worked flawlessly, and heated up more quickly since the burner is now operating at full output. YMMV

Nice work. So it sounds like the problem was the thermocouple being misaligned was causing it to not get hot enough and would close the gas valve under certain conditions. Sounds like wind just exacerbated the issue. Is this right?

I've posted this on the other thread you linked but here is the link to a new electrode assembly that should work with the Suburban SW6D(E) if anyone ever needs one:
https://www.amazon.com/Suburban-2322.../dp/B003G9IYQY

[CharlesinGA]

Apparently the igniter probe does double duty as a temp sensor to know the flame is lit. My Atwood does something similar. It will lite off, burn for a few seconds and quit, try again, and try again usually staying lit on the third try. Sometimes I have to reset it. I have not taken the time to look at it but this is a lightly used water heater, so the probes should be in good shape. I will investigate and see if it needs to be relocated more into the flame.

Charles

[rocky47]

I think the problem is made worse by the fact that the Suburban, unlike a domestic water heater, does not have a thermocouple. Rather it uses a flame sensor which relies on the fact that the ionized gas present in the flame conducts electricity better than the non-ionized gas when there is no flame. See this for an explanation.
https://hvacrschool.com/flame-sensing-the-basics/
I would, however, not suggest using the test described in this link since the Suburban uses the same electrode for ignition and flame sensing. The high voltage applied during ignition would not be appreciated by your meter.
The use of this sensing method means that if there is no flame, or not enough of the flame, between the two electrodes on the ignitor, the heater controller will assume that the water heater is not lit and shut down the gas supply. It will then try to re-ignite 3 times and, if that fails, call it quits and turn on the small red light between the water heater and water pump switches.

[jkavanagh]

Why does the AC make a clicking sound when the furnace is starting? We do not have it on fan.

[rubicon327]

Originally Posted by jkavanagh

Why does the AC make a clicking sound when the furnace is starting? We do not have it on fan.

This thread you posted to is talking about hot water heaters but check out the below link. Not sure what thermostat you have but what I provided in post #3 worked for cpaharley when he had clicking...
https://www.escapeforum.org/forums/f...tml#post313588

[jkavanagh]

Originally Posted by rubicon327

This thread you posted to is talking about hot water heaters but check out the below link. Not sure what thermostat you have but what I provided in post #3 worked for cpaharley when he had clicking...
https://www.escapeforum.org/forums/f...tml#post313588

Thank you, I am now warm without the clicking sound from the AC. Looked at the link and followed the instructions and it worked. Even though I posted on the wrong thread. This a great forum for help . Judy

[rubicon327]

Glad it worked!