Asked on Mar 8, 2013
Gas heater makes a loud intermittent noise from filter doesn't stay up in place.
We are using the correct filter size and it happens when they are new and have been in use. The noise seems last about 3 minutes from the time the heater goes on and there's no noise when it goes off. We think the filter is flapping around until its pulled into a solid position. Can different brands of filters vary in size or construction some how?