Tepid hot water

[tiinytina]

Sent: 4/21/2007

hi ho,
   furnace works... now no hot water.... oiy. Its always something ain't it?
ok... igniter clicks away... flame is on.... makes a sort of guttering sound and igniter keeps kicking in intermittently. Water only gets a click or two off cold after 30 min... Black soot mark from heater exhaust.... with heater off blowing air into intake.. produces flakes of soot flying out. I took off the pipe between gas valve and ignitor.. all clean no nests etc. When heater turned off small flame for a bit from end of gas valve orifice. Have not put compressed air into the intake yet.
   I actually thought this was due to a windy night as it was very windy with the wind blowing directly into the unit but... it continuted the following day without wind....
  we have recently detached gas hoses from the furnace/stove etc to work on them. I'm wondering if some bit of something has partially clogged the gas valve so its just not getting enough. I did try adjusting the air flow after the valve but this had little to no effect.
   Can I remove the gas valve and clean it without damaging it by blowing compressed air through it etc. I tried removing the gas orifice at the end but it looks like I need to remove the valve and put it in a vice etc... to get the fitting off. Just bought a new valve for the furnace and that was $102... we tried cleaning it and screwed it up....
   I did a search on water and gas but didn't find anything.... don't know what kind of heater this is 1987 edition of whatever, electronic ignition...

Thanks!
Tina

[salplmb]

Sent: 4/21/2007

hi tina,
the gas valve for the water heater can not be blown out with air. if you do this you will most likely ruin the unit. they are made to run on a very low pressure and putting a higher pressure to them than they are made for will ruin the valve. you can try to remove the valve body from the unit and look at the intake port. some have a screen which can get clogged. other than that i would check to see if all the ports are clear. if the unit fires up and lites it is probably still a good valve. pull the gas line to the valve and see if you are getting a good amount of gas. it kind of sounds like a mixture problem?
hope this helps a little.
sal

[bluebird]

Sent: 4/22/2007

Hi Tina. If you have soot, you have gas, but no air. The problem is most likely in the mixing bud right at the end of the tube. It either has a spiders net or it's full of rust. The problem is after the gas orifice, this time.

Chuck.

[Slantsixness]

Sent: 4/22/2007

Tina,

No joke here.... How old is this water heater?

Something is clogging the air input to the orifice or Burner. If you continue to have soot come out of the exhaust and no hot water, it keeps re-igniting etc... there is a potential problem that the gas will / can ignite where you have more air... as in...OUTSIDE the Water heater fire box! It can set the rig on fire.
You must fix this!

DO NOT USE compressed air on orfice tubes, you can destroy them. If the air intake port is clogged, remove the debris. remove the burner assembly and check for clogs/nests/ mud wasp nests etc. Ensure that the burner cavity is free of this debris.

If your burner is old and rusted out.... then it could burn only on the very edge, like a gas grille where the burner rusts out: Lots of flame, but not directed into the cavity, thus: no hot water.

Take it completely apart.... then you will find the blockage. Or, the burner assembly is bad or rusted out. If that is the case, I would seriously consider replacing the entire water heater over repairing it... Why? Because at almost $300, it's certainly better than replacing pieces and parts and possibly burning your rig to the ground trying to save money, and in the end... a new burner and igniter and orifice and control board (if it has one) costs more than a whole new water heater!

My wifes grandparents had this happen. Their rig didn't burn, but they had a 7 foot tall soot scar on the rig (took 4 hours scrubbing the rig to get the scar to "barely noticeable") And for what? a wasp nest encasing half the burner, that I couldn't see until I pulled the burner out. Luckily, we got the nest cleaned up with some elbow grease and a wire brush and all is working now.

Tom

[tiinytina]

Sent: 4/22/2007

thanks.... all...

Ok so... can't do a blow through of the valve but can I use a compressed air blow and go from after the igniter through the exhaust?

the unit worked perfectly in January at the plunge....  soot line now is only about 12" above unit....I tried adjusting the air control via moving the pipe closer farther via the adjustment screw thing... but it did not improve the flame.   Obviously the flame wasn't just blue but with alot of orange/yellow so I knew it wasn't burning cleanly.  I'm just thinking after tinkering with the line at the stove and furnace which are before the water heater junk just got dislodged...   do you think taking off the gas valve... cleaning off anything I see in front of the valve and after might help? 

The water heater is 20 yrs old (can't tell you what make and model as I don't. know).

Doesn't appear to be a nest in it.. as it worked fine before other propane work.. and it was winter etc.... so no wasps etc....

Tina

[salplmb]

Sent: 4/23/2007

hi tina,
you can blow through the burner line after the valve. you would be surprised at how little a piece of something can mess up the valve. there should only be three lines coming out of the valve itself. one for intake(gas line), one pilot, and main burner. there is also a thermocouple coming out of the valve. no gas through this device. not sure what make you got but it should be pretty easy to get to. i would pull the main gas line and turn on the propane to see if stuff is still coming through the line. if not move on to taking out the valve. you want to make sure that if some stuff is coming through the line that after you are done it dosen't do it again.
good luck and let us know how it works out.
sal

[Wendell]

Sent: 4/23/2007

I think I'd just replace the whole water heater and sleep better.  When I got my rig, I had a similar problem to yours, and the P.O. had apparently tried to fix it, but there was evidence of some major problems (melted plastic, smoked up and singed parts, etc.).  I just pulled it out and replaced it with a new one.  It wasn't that hard to do and now I have plenty of hot water and I don't worry about the rig catching fire (at least not from that source).

Twenty years is a lot of age on one of these.   

[tiinytina]

Sent: 4/25/2007

thanks for all the thoughts. I bought a new burner and installed it, (the old one was old and rusty but was working fine in January last time out) I'll have to fiddle with alignment after valve is back in place. I just love that they used a self tapping screw to attach the burner to the intake tube, can only get a small pliers in to turn it, not enough clearance for a small ratchet) Igniter works fine and tank etc seems in good shape. I removed the gas valve and removed the orifice. There was a tiny tiny piece of something clinging to the inside, not near the actual orifice though... so took out the cotton swabs and alcohol... There was a mud dauber nest plus flurg in an opening on the top of the valve but the hole that this was in doesn't seem to go to anything but I cleaned it out anyway.

Putting everything back together tomorrow if it isn't raining. (and yes I turned the propane tank off before I tackled everything, in fact turned it off when we parked her 2 weeks ago).  I'll also hit the intake/exhaust pipes with some compressed air to get out any remaining soot flakes.

tina