Ward Burner Systems

Customized Combustion Equipment

Baso Valve; New One Not Working?



by Marc Ward
Clay Times Sept. 2003 


    Every once in awhile I get someone who calls up and says; “Hey, that BASO Safety Valve you sent me is no good. I hooked it up and it doesn’t work.” This past week, I had one of those calls…

    It started as usual with someone describing how they had the new safety valve installed on the line, hooked up a new thermocouple, pushed the button down, lit the pilot, and got nothing happening, nadda, no gas going to the main burner,….nothing. In this particular incidence, they had folks from the local heating and air company doing the installation. They couldn’t get it to work, so they insisted on putting another valve on the gas line and telling our frantic, “I’ve gotta’ fire my kiln cause I have a show coming up”, potter to send the valve back. So, send it back they did and asked that I take a look at the “defective” valve. I promised I would look at it and perform a bench test. Soon it was on its merry way inside a big brown truck driven by an equally merry member of the Teamsters Union. Shortly, my always faithful, UPS worker-bee delivers the offending valve and I proceed to test it.

    It works perfectly.

    So, what gives? This isn’t the first time I’ve tried to convince someone that these things aren’t defective outa’ the box. And, in this case, some of the people saying it was defective were professionals in the heating and air business… HVAC is the name for all things that fall into this brand of business (Heating, Ventilation, and Air Conditioning). The HVAC guys say its bad…, so it’s bad. Who’s going to argue?

    As with many things in our “fixitnow” technological society, symptoms are often mistaken for the actual problems. When a low gas pressure BASO valve doesn’t work, it better to start off looking at the actual problem that to pay for a new valve (treating the symptom).

    A BASO safety valve receives a small millivolt signal produced by the flame on the thermocouple. This signal provides enough electrical current to cause a small magnet to pull a lever over that keeps the plunger in the valve from closing off. Not enough signal, and you can’t get the valve to stay open…. Lose some signal while the burner is on and the plunger drops down and shuts the burner off. The problem is usually the signal, not the valve.

    So, before you race out to buy a new valve, there’s a few things you need to try to determine if you want to treat the problem or the symptom.

    A thermocouple needs to be in blue flame continuously. Not a sort of blue with some yellow. And, not for 9 seconds out of 10. A blue flame continuously. So, you look at your pilot flame and these conditions exist. There are a few other things to try. The first thing to do is to replace the thermocouple with one you know works. If this doesn’t do the trick, you need to give it a good poke. I’m not talking about using a sharp stick… you need to give the voltage a good poke. You can do this by taking a hand-held propane torch and heating up the tip of the thermocouple until it is glowing hot. Many times, this sorta’ jolts the little electromagnet in the BASO and “wakes” it up from its slumber. If this doesn’t do it, you might try cleaning the contact inside the BASO where the thermocouple goes in. Use a little alcohol on a Q-tip. Oxidation may have built up on this connection and prevents our small electric current from getting through. This can be especially true as with our frantic potter. They lived on the coast with plenty of salt spray in the air. Small electrical currents in the presence of salt can really build up a corrosive film.

    Before you tear your system apart to replace the valve, try these tricks to make sure you know where the problem is. Remember, as with a bunch of stuff in life, the “identified” problem is, many times, just the symptom.