Possible the model is SW6D? I do not find Swd6d, so I've gone with skipping the one letter and think it is correct.
So some ideas are pretty easy to check on this one as it is direct ignition. That means no pilot light to think about as it has an electronic "clicker" like bar-b-Q etc. have. Good thing is that there are few parts to think about but then it gets into the control board where we can't see or tell if it is good or bad.
Since you have one that does usually work after a while, I'm thinking it is not the board but possibly something we can see and feel.
I stole a snip off the internet for reference to make it easier to talk about.
First, verify this looks like what you have?
If it matches, try looking at the heater while somebody else turns it on inside.
You should hear the igniter clicking and if close enough possibly see the sparks. Those sparks are likely to be what messes with the TV signal! That leaves me thinking it is working up to that point.
Second point to make sure of is that there is not something restricting the gas flow through that metal tube going to the right. Wasp or mud dauber nests are frequent items that do that, so it may help to stick a wire, etc in and scrape the tube a bit to check for that. They often hand them on the top side to hang down! A leaf vac, hair drier, etc can help clear any loose debris you knock loose.
Screens over the vents are a good idea if not in place?
Warning!
Don't stand too close when first checking this as it may be aproblem that the clickerworksand then you should hear or feel the gas solenoid click as it opens at number 2. The problem can be that the valveopens but there is something like a wasp nest in the tube where the gas flows to meet the ignition clicking! If that tube is stopped up partway, the gas may not go into the tube as it should but piles up at the air opening before catching fire.
It's not a lot of gas but not something you want to be real close to if it does light!!
Simple idea is the inside switch turns on, the igniterclicks and then the gas valve opens with a click to let the gas flow into the tube to meet the igniter and you get fire!
The red reset buttons were already markedon the "stolen" drawing but they only come in if the heater has over heated and then they need pushed to reset after it cools. I've never had it happen but something to know?
See if that makes things better. It could be the board but boards are not too prone to fixing themself at different times, so I'm moving away from that idea untilproven different?
Linear Mode
