Hot Water System Dilema

I want to thank John and HJ for their help - I really appreciate their contribution to this forum.

I felt I should post an update on this situation to share with the others my experience. After all, we are here to help each other.

Since my last post, I had another licensed plumber come out and give me yet another completely different solution. To be honest, I wasn't confident that the three plumbers that submitted proposals knew what to do. While I value John's suggestions highly, I was confused and not sure what direction to go.

I decided to call Bell and Gossett and see if they could help me. They referred me a local distributor who also provides product support. What an amazing resource I discovered! The B&G rep asked me to fax the details of my home and heating system. Within 3 days, he emailed me a list of parts and requirements to rebuild my heating system from scratch. He and an engineer took my data and calculated flow rates, head losses, etc. I'm very confident their solution was well thought out and planned. My advice is if you are lost or want a professional second opinion, do not hesitate to contact the manufacturers. I know at least B&G stands behind their products and for that, I am and will be a loyal customer.

I'm going to start this project this weekend. Please see the plan below.

1. Combine first and second floors into one zone. Additional zone for basement baseboards will be added later.
2. Use 1" PEX with Monoflow tees feeding 1/2" risers to the cast iron radiators.
3. Keep existing 1" main supply and return lines.
4. Replace zone valves with two B&G NRF-22 pumps for each zone
5. Install B&G EAS for air removal.
6. Install B&G Z-2 relay control box for zone control.

Conclusion

I finally completed this project over the past weekend and wanted to follow-up with a conclusion as my experience may help others. I would also like to thank everyone who chimed in on this post as your suggestions/comments were very helpful.

My final configuration was all copper piping, 1" main with 1/2" risers. I used B&G branded monoflow tees, one per riser, and a B&G NRF-22 pump. I also added a LWCO and a B&G relay box. The main was installed flush with the bottom of the 1st floor joists to better accommodate the finishing of the basement.

I completed the final piping and wiring of my new monoflow system Sat morning. I filled it, bleed it, and fired up the boiler. I noticed right away, how much faster the radiators heated up compared to my inferior 1/2" PEX series looping. Mind out the house was around 74 degs inside but you can feel the heat coming off those things immediately. I temporarily wired the thermostat wires to light switches since it's too hot in the middle of the summer in NY. I ran the boiler till the water reached 180 and shut off. I let it cool to about 120 and fired up again. I did this several time to make sure no leaks and system working as intended.

I must pat myself on the back as no leaks at all. Furthermore, the monoflow system worked beautifully. Since it's the summer, hard to gauge whether or not the radiators are heating evenly, so I used an infrared thermometer to measure the supply and return temps for each convector. I also checked the temps of the right and left, top and bottom of each radiator. They will were all equal, around 160-180 degs, so I am convinced the monoflow tees are working as intended. I did notice I had to bleed more air out of them compared to the series loop but nothing terrible.

My only complaint, and I don't think there is much I can do, is the noise the pipes make as they heat up and expand. Since I ran the main and riser pipes flush to the bottom of the floor joists, as they heat up, you can hear a lot of creaking and cracking as the pipes move around. I used copper clamps to hold the pipes and they do not allow for any movement. I was thinking of replacing those with plastic PEX talons and pipe hangers mounted loosely. I do realized this will probably not remove all the noise but may help. Any suggestions here appreciated.

The final test will be this winter but I'm confident the heat will work properly. This was a major job, estimates from local plumbers were $3000+. In total, I spent about $1800 in materials and countless hours but I'm happy with the results.

Thanks again - Jason

To alleviate the creaking and groaning when the pipes expand and contract the pipe should not touch any structural supports (floor joists) or flooring where it passes through the floor and it should be hung (not clamped) in a manner that allows free movement of the pipe. I used "U" straps made from perforated metal "plumber's strap" that cradled the pipe (better is to cradle rigid insulation over the pipe) from the overhead structure.


Just about anything would be an improvement over a series loop that used 1/2 inch PEX. The only problem with a Monoflo system is that it is sometimes more resistant to complete bleeding of air.