SuBurbank hot water heater

[Harleyhippie]

Hi. I have an SW6d. I replaced the thermostat and the electrode and cleaned the burner tube. I get the three 3 sets of clicking but it wont light. I manually lighted it and it stays lit until the clicking stops. I have even talked to Suburban and they don't know what the issue is. There's no problem with the gas flow.
Any ideas? I haven't had hot water since the beginning of November. It's getting old taking buckets of hot water into the shower 😞

[trailrider]

Harleyhippie wrote:
Hi. I have an SW6d. I replaced the thermostat and the electrode and cleaned the burner tube. I get the three 3 sets of clicking but it wont light. I manually lighted it and it stays lit until the clicking stops. I have even talked to Suburban and they don't know what the issue is. There's no problem with the gas flow.
Any ideas? I haven't had hot water since the beginning of November. It's getting old taking buckets of hot water into the shower 😞

You say 3 sets of clicking. But are you actually getting a spark across the electrodes?

You also say it will stay lit until the clicking stops if you manually light it. The flame goes out after the clicking stops?

It would have to be the circuit board or the wire connecting the circuit board to the electrode.

[Harvard]

A common fault with the older (2004ish) Suburban WHs are open Gas Valve 12V Solenoids. There are two identical 12VDC gas solenoids, the coils should measure about 40 Ohms each.

[Davidlee64]

I was running into an issue with mine. Same model WH. I would take the nozzle out, run a toothbrush across the end where the orifice is, reassemble, and it would work for a while. Eventually I won the battle and it has been working since.

[jerryjay11]

All electrical connections must be tight and the control needs a good ground. Check first. This is a common problem even on residential equipment.

But:
Sounds like a partially restricted burner orifice. Poor flame across the igniter which also sensor for flame. Because you say it lights when you aim an external flame at the gas I have to believe the flame is crooked or weak it won't be sensed properly. Pull the orifice, blow it out with air or replace. DO NOT POKE IT WITH A WIRE!

If you light it with a propane torch, leave the torch lit with the flame touching the igniter to see it it will stay lit once the clicking stops. If it does it's a flame issue if it still goes out it probably in the control.

I am assuming the igniter did spark in the first place, but you didn't mention if it did. That should be the clicking you hear.

[2oldman]

Have a RV tech look at it. Yes, money will have to change hands.

[GordonThree]

Does the new electrode get nice and hot so it's glowing? What about the electrical connection to the electrode, did you clean or replace it?

The heater uses the electrode to confirm the flame is lit by running a high voltage charge through the flame itself. The current is tiny, microamps, so it doesn't take much corrosion to interrupt.

If you don't see anything, next step is an RV tech with an analog micro-ammeter to diagnose the flame sensor and control board.