Id recommend that you test the polarity to your BBU. If ok, ensure that your getting 240v to the appliance..If your getting a spark at the pilot and no flame, check if there is gas to pilot, at time of ignition..you have an oxy pilot and if there is fluff-lint, around the pilots air port then it will not light. try these checks ...post me the results ...good luck....ps you have to be gas qualified to work on any gas appliance