Hello, My Grundfos pump circulator for the family room hot-water base-board heating system (zoned) does not operate. Could someone please kindly shed some light? Thank you in advance! Background Info: The ciruclator's model number is Grundfos UPS20-42F (I believe the newer replacement model is UP15-42F). When I turn up the thermostat in the family room and move across the temperature threshold, I hear a fairly audible click from the utility room right next to the family room. However, upon a close-up checking, the circulator did not seem to be operating (no vibration felt from the housing and no pumping noise). Both shut-offs on the circulation path were open and no heat was felt at the fin-tubes. Somebody on the web talked about a capacitor that can go bad. If that's the case, what is the function of this capacitor and where is it located? The circulator (pump) has a slotted circle on the top of the house. Looks like something that one can turn with a flat screw driver. What is the function of that? Other potentially useful info: The gas supply was shut off last winter (by the previous owner) and there probably had been a deep freeze in the pumbing system. As a result I have to replace a section of the fin-tube that had gone cracked. Could the deep freeze hurt the pump? The rest of the house has hydronic floor radiant heating and they are all still in good working condition. hsieh

I need to replace a leaky union that's located in the main piping coming from the boiler. The pipe diameter at this point is 2 inches. I can't get it to budge. If I put an extension on my 24" pipe wrench and use force, I end up pivoting the boiler. If I try to tap the wrench with a sledge hammer it won't break free. I'm afraid to hit it too hard because I don't know if I could damage the boiler. Would heating up the pipe with a torch help? Note that I don't know how long this old piping has been together. My house is 80 years old and I have steam heat.