New System Complete

Ocelaris

I thought I would share some pictures of my boiler repiping that I just completed. Thanks for all the great discussions which helped me plan and implement this. Long and short we had the original boiler replaced from the 1950s (200k+ net unit) with a 100k unit (80k net) 2 years ago, and it was apparent that something was wrong. It was a monoflo system and it was condensing, also we needed a second zone in the basement and I wanted it done right this time.

We split the house up into 5 zones and used a taco i-series mixing valve for ODR and boiler protection. 1 1/4" piping for the near boiler piping and 3/4" take offs for the grudfos alpha pumps. I had ordered a bunch of books from Dan Holohan about pumping away, so hopefully you all don't find too many faults with my piping. We tore out the 1 1/4 copper that was hanging down in the basement and used viega fostapex, pex-al-pex 3/4 in a reverse return arrangement for everything. After doing hundred of connections, sweated, threaded and pex I only had 5 leaks, of which only took an afternoon to correct. Some of these pictures are at various stages, but there is a dirt separator on the return of zones, and the air separator is right at the beginning of the supply before the pump. Most importantly it works, I have the boiler set to adjust between 165 and 180, and the i-series mixing valve was putting out between 95-120 degree water to the zones when I tested. I put the outdoor reset sensor resistor in a bag and then put it in a cooler with ice. Also for the basement I bought off craigslist about 6 radiators. I wanted to roughly match what we had upstairs (sunrad) but I couldn't find all hot water so I ended up with 3 hot water and 3 steam. I ground off most of the paint and painted them myself. I had to change out most of the fittings and tap air bleeder valves to the 3 steam ones (and plug up the old holes). It's been a long process, but glad to be done (mostly).

Thanks, Bill

bob_46

Bill, you need to rotate the pump ahead of the mixer so the shaft is horizontal .

Rich_49

Sensor connx must also always be over the supply water pipe .
The head on your unit should rotate 90* counter clockwise . There is also no necessity on doing P/S piping arrangement to insure boiler return protection . Taco's literature shows it that way but I assure you it is not necessary . You are not the first to not realize this fact .

http://www.taco-hvac.com/uploads/FileLibrary/102-144.pdf

bob_46

Rich, if you don't pipe pri/sec aren't you putting the boiler loop pump in series with the zone pumps more or less depending on the position of the 4way ?

Rich_49

Don't need that pump if you're not P/S either . No minimum flow requirement on cast iron , only return water temp is a concern . Hot boiler water mixing with returns leaves plenty to protect the boiler .

Zman

bob said:

Bill, you need to rotate the pump ahead of the mixer so the shaft is horizontal .

Everyone has a different way to go about it. This is the item that should be changed