Is it normal for the water pressure gauge to only read 0-5 PSI? When the furnace turns off at ~ 180F, the water pressure is about 4-5PSI. There's considerable amount of water deposits coming out from the expansion tank safety valve and a lot of gurgling in the baseboards. Based on my experience when I had a hot water furnace the gauge should always read 10-15PSI. Not looking to DIY, just determining if this is normal and, if not, how long I should wait to call a service tech. Thanks in advance.