Here's some photos of my finished DIY Biasi boiler install, which was started last year... Over the summer I added a TV valve for boiler protection, and also added P/S piping for the heating system. The system is monitored by Tekmar 260 outdoor reset controller. The electric water heater is temporary and was used for hotwater in the past--I'm going to move it and store it for future use as needed. The P/S piping allows using a boiler minimum well under 150 degrees, since the TV valve always keeps the return at 140 degrees or higher. So far it is working great. NOTE: this install was done under a building permit and inspected, and a modification of code was granted for the wood boiler emergency backup boiler. Pete [url]http://i117.photobucket.com/albums/o46/radioconnection/PSpiping2.jpg[/url] [url]http://i117.photobucket.com/albums/o46/radioconnection/PSpiping3.jpg[/url] [url]http://i117.photobucket.com/albums/o46/radioconnection/PSpiping.jpg[/url]

I have a Peerless 85 series hot water boiler (not sure of age). Several years ago (before we owned the house) the cast iron radiators were replaced with ¾ inch copper baseboard heaters with ½ inch pex running to them. We’ve had problems with the system ever since we moved in. When the system is running, the pressure reading on side of boiler goes up to about 34 psi and the pressure relief valve drips/runs. I have a steel expansion tank mounted up between the floor joists which I purge quite often (more than weekly in the heating system). When I purge it expansion tank this stops the dripping at the relief valve (for a while), but then I get air bubbles in the system. Gradually over the course of a few days the bubbles go away but then the dripping at the relief valve starts again as the pressure builds up and I end up doing this all over again. The problem seems to be getting worse as I have to do this more and more frequently. Lately I have taken to shutting off the incoming water feed to prevent the pressure from gradually building but obviously this is not a permanent solution. Is the pressure reducing valve on the incoming line bad (it says it’s set to 12psi with a range of 10-25)? Do I need to replace the expansion tank? Is there some other element of the system that controls pressure? I think the temperature might be too high too (210-220 F according to the pressure/temp gauge on the side).