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Rick, HVAC Supervisor
Category: HVAC
Satisfied Customers: 19164
Experience:  40+ yrs. experience as a licensed oil & gas technician.
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I have a LAARS Mascot 330 + years now. Recently,

Customer Question

I have a LAARS Mascot 330 for 7+ years now. Recently, we the unit is turned on (hot water or heat), we are hearing a noisy shrill whistle noise. It wakes up at night :-(...
Any thoughts on what's causing this noise?
Submitted: 6 months ago.
Category: HVAC
Expert:  Rick replied 6 months ago.
Welcome to Just Answer, my name is ***** ***** I will do my best to help you with your issue. If my initial response doesn’t answer your question then let me know and we can continue our conversation.Th first thing to check is the gas supply and manifold pressure. Pressure that's too low either in or out of the gas valve can cause an annoying whistle. If the unit hasn't been serviced in a while or the combustion chamber/burner have never been cleaned then doing that would also be a good idea.