I have a new boiler installation with five new Taco 007 Cartridge Circulators with integrated flow control. One is for the boiler secondary circulator and the other four are for the zones. Three of the four zones work great. The forth is giving me problems. When its zone calls for heat, the pump turns on normally and sometimes will circulate the water and other times will not. When it works normally the zone comes up to temp like it should. When it doesn't work the zone return pipe is cold and the boiler reaches it's upper temp limit and turns off while the pump keeps spinning forever until I shut it off. I removed the new circulator, inspect it for blockages, removed, and inspected the integrated flow control valve which is a very simple device and all appeared to be fine. I reassembled and reinstalled it, purged the zone pipes until all air was removed and the water was very clear. Turned it on and it worked fine - for about a day, Then it would not circulate water again. So I again removed the pump, again checked the IFC valve, this time replaced just the circulator pump with another new one, reinstalled, and purged the lines again. Worked great - for about another day, then the same problem. The zone pipes are not blocked, water flows freely when purging, the input manifold is a new 1 1/2" pipe and works perfectly for the other three zone on the same input, the circulator pump is getting full voltage, nothing is wrong with the relay or wiring, I can hear and feel the circulator turning. The IFC valve is new and looks perfect with nothing blocking it. The water pressure is 15psi which is correct. So why on earth won't the water circulate? The only explanation I can think of is that this zone serves the highest (2nd) floor and that the 007 pump can't handle it. But this installation was a retrofit and the old boiler had a 007 pump for that zone and it was working fine for years. I've never used the Taco IFC valves before (always used swetcheks) so maybe that has something to do with it. I'm at a loss to figure this out. I need someone with experience or insight to help.

My new Biasi B4 was installed with a heatwise propane burner by the contractor that built my home in 2004. It has always purged excessively before firing up. After complaining about it, the blame game began between the builder, the plumber and gas company. Each of them came to inspect it and each said they can't find a problem. I called the gas company and they verified the pressures were correct. I recently hired an independent plumber this summer who found that the chimney flue damper was broken and replaced it. He also vacuumed the vessel from soot. Although, the cleaning seemed to improve the air flow and the boiler did fire up after 3 or four purges during the summer, the problem is not fixed. The purging is again excessive and the boiler even shuts down for an hour after maxing out on firing attempts before it starts to try to fire up again. I've been shopping for a plumber, but it seems that if the unit is not one of the top 5 most common high efficiency boilers, plumbers are reluctant or just out right refuse to deal with it. I need to find someone that is willing to perform all of the tests necessary to determine if the unit was installed EXACTLY to specs and not recommend that i buy a new system because they know other brands better. Nobody seems interested. I don't understand what the reluctance is all about, since I have manuals and spec sheets for the system. What can I do to find someone that really knows his trade regardless of brand?