Williams wall heater shuts off

ezwriter

We have a fairly new Williams wall heater that runs about 5 mins then shuts off and pilot is out. Manual says pilot may be too high and blowing out ,the flame does seem too big but there's no adjustment screw where the manual says to adjust it. Help! my kids are cold! Thanks in advance.
kEN

bflaska

Hello to all you intrepid DIY's

My first post here and I have a problem. I have Williams wall heaters (2 years old) that were installed by a heating company before I bought this place.

One heater is silent when running. The other one clanks clanks clanks like expanding metal when it's heating and then the noise stops. Then it clanks clanks clanks when it cools down. What the?! Any ideas what the problema might be and more importantly how to fix?

Thanks a bunch!

jogr

Sounds like you know what it is - expansion and contraction. Tough problem to fix. Usually some piece of sheet metal somwhere. See if you can identify exactly where the noise is coming from and see if you can adjust that piece.

I was almost going to suggest opening up both and seeing what is different between the two but it occurred to me you just might end up with two noisy heaters instead of one! Better to leave the quiet one alone.

Irishkid1973

I have a very old Common Wealth wall mounted heater that started popping loudly every time it turned on or off from metal expansion. What happens is, screws holding the heat exchange manifold (The main part that gets hot) will start to corrode or are over tightened. You can not stop metal from expanding or contracting so tightening up screws will only make the noise louder, in most cases. Simply loosening the screws just enough to allow metal to move 1-5mm unobstructed will make a noisy heater quite right down. In my case the heater was waking me up every time it turned on or off but now it only makes a slight click every now and then. AHHH quiet heat.

hvaclover

Sounds like the heat exchanger is very noisey.

__________________
Just slow, not stupid.

Irishkid1973

It is not the exchanger that is creating the noise; it is just expanding or contracting. The noise comes from the outlining screws that mount the exchanger to the frame of the heater. As it expands or contracts, the exchanger mounting locations are trying to move under a screw that is gripping it. Eventually the exchanger wins, breaks the grip of the screw and POP! The sound is then amplified by the exchanger; it's basically a big sheet metal drum.
Oh one more point, some of you might be tempted to spray the screws with lube. It does work to quiet the noise for a short time but then you run the risk of fire, the smell of burning oil is toxic and will linger for a long time afterwards, so don't do it, even with high temp sprays.

Omegaman

The idea that one part is espanding and contracting whil another is not, and then slips under screwheads seems reasonable. Loosen the screws and allow it to go through a heat up and cool down cycle. I the noises are gone, then that was the problem, if not, then look somewhere else. Mind you, this should be a temporary action, not a solution, retighten when finished with experiment.

If you discover that to be the problem, then there may be a solution, though not an ideal one. Since what is happening is that one item is expanding while another is not, this means that there is a temperature differential between the items. If you can reduce or eliminate the differential, the problem might go away. I suspect that one item heats, and the other does also. Perhaps, if you turned the gas petcock partially off (in the bottom of the unit - follow the line from the control to the supply) you would effectively lower the BTU of the burner assembly. If you do this, be sure to observe the color of the flames in the burner - if they remain the nice blue as described in the manual, but are just a bit shorter, you should be o.k. If the flames go yellow, abandon this idea.

In this way, the heater will not heat up the rapidly expanding part so fast, and the other part might get some time to catch up. Of course, the room wil not heat up as quickly, but most likely it will still reach the desired temperature. The cycling of the control (if thermostaticaly controlled) will be reduced and it an the burner and heat box will have a longer life.

Now the disclaimer> I have worked in the HVAC field, and I have done this on my own Williams wall unit, and it worked. Never-the-less, I do not claim to have suficient expertise to evaluate this method as sound or safe, so you should consult someone more qualified than I, and assume all risks for your own actions, as well as not attempting anything that you do not understand. Good luck.

SKIP4661

May be that an eco/vent switch is in the circuit with the thermocouple.
You can locate this switch at the top of the furnace near the draft diverter/opening for vent.