Had to check a mcquay rooftop unit model RPS, tries to start and goes out on flame failure. The maintenance guy says that it will only fire if he cover the inducer fan intake, anyone ever run into this, could it be a problem with the pilot tube?
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Had to check a mcquay rooftop unit model RPS, tries to start and goes out on flame failure. The maintenance guy says that it will only fire if he cover the inducer fan intake, anyone ever run into this, could it be a problem with the pilot tube?
Pull the burner assembly. Could be pilot orifice, crossover tube, rotted brackets or a combination. Also could be a restrictor plate rotted out by the inducer.
You definitely want to check main gas pressure first. If a pressure regulator is used for medium pressure gas, verify that it is not locking up and on start up not opening completely. For this you will need a manometer.
After that verify that manifold gas pressure is correct based on design.
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Trouble shooting is not part of the repair......understand the symptoms and you will find a solution.