zone pipe work

nytech28

hello, I will be replacing hose bibbs & gatevalves on each  3/4 zone pipeline , due to tight corners I want to add unions to each zone pipe to easily remove pipe & replace parts, unions  will also help  remove pipe out of way when replacing boiler in near future.I would appreciate any recommendations on my thought process  & also will attach pictures as reference 

EdTheHeaterMan

@DanHolohan has an excellent solution to this. He calls it a "Pumping Away Module". You only need one connection for the hose. All the zones are purged from the same outlet. You can ram up the pressure to over the relief valve pressure without blowing the relief valve. This higher pressure will allow for entraining air from second and third-floor baseboard radiators and forcing it back to the boiler room where it can be removed at the purge outlet.

I can't find the article about it, however, it is explained in his book "Pumping Away"/

Tinman

Honestly, that's a mess. I'd recommend re-piping re-wiring everything from the boiler to the ceiling.

3/4" supply and return mains coming off the boiler? Unless, the boiler is 40,000 BTU or less, they're too small.

The strap that's supposed to be supporting the tank, has slack in it which means it's not really supporting the tank.

Pumping away from the point of no pressure change is always a good idea. The PONPC is the expansion tank. Move the pump to the supply and tie in the tank upstream of it.

Use isolation flanges on the pump and install a ball valve inline with the tank.

Use a Zone Valve Relay to clean up the wiring. It will activate the zone valve, the pump, and the boiler.

Maybe a wash and wax too?

EdTheHeaterMan

Several other observations.

The manifold that feeds the zones is 3/4" copper and the boiler is surely larger than 100,000 BTU (judging by the size of the Jacket) That common pipe can not allow more than 40,000 or 45,000 BTU of heat to pass. This means the boiler is doomed to short cycling during design conditions. You may even experience insufficient heat during very cold weather.

The venting is incorrect for the type of boiler. Galvanized vent pipe is not rated for positive pressure venting. The pipe should be increased to 5" or 6" at the blower exit. The red caulk is not a proper solution to the problem.

There is obviously a situation with the expansion tank. Is the water on the floor from a leaking relief valve or is that all from the valves you want to replace?

The zone valve wiring is difficult at best, but I put that in the "if it ain't broke don't fix it " category. You can address that if and when the problem presents itself.

May I use this picture for "What not to do" in my next class on Hydronics?

Now here is the piping design from "pumping away" for your system.

EdTheHeaterMan

Explanation:

Valve A is the water feed that has full house water pressure. The green arrow indicates the direction of the water flow. When it gets to a Tee the water will take the path of least resistance. By closing Valve B the water must flow towards the radiators and build up pressure in the system. If valves D, E, and F are closed. the pressure builds up in the radiators and piping with potential energy ready t force air to go down the pipes from the second and third floors. Now there is pressure on the system however the relief valve G is not seeing that pressure.

Open boiler drain valve C with a hose connected to it. Now using the full house water pressure, open valve D and the water will force the air out of the pipe and radiators on that loop only.. the air will be forced into the boiler, and eventually (pretty quick in your boiler), the boiler will fill with water. Once there is no more air from valve D zone, then close valve D and open Valve E and purge that air from the radiators and pipes. Once there is no more air in zone E then close valve E and open valve F. The air from that zone will be purged and once the hose shows no air from that zone you can close valve F.

Now, most of the air is all gone. Enough for the pump to circulate the water in the system. Close valve A (or set the auto-feed to the boiler static pressure (about 12 PSI). Close Valve C then open valves D, E, and F. Adjust the pressure to the desired Cold Static water pressure by adding or bleeding off water as needed.

Your system is ready to be commissioned.

This is only one reason to use pumping away. There are more reasons to design the piping in the exact order shown,
Finally, the common pipe fro the zones should be large enough to accommodate all the zones. Use at least 1" piping to accommodate 80,000 BTU of total capacity or use 1-1/4" common pipe if you need more than 100,000 BTU of capacity

If 3/4" was all that was needed for the supply and return openings the boiler would not be 1-1/2"... They would be 3/4" openings. It's cheaper to drill and tap a 3/4" hole. One thing a manufacturer would not do is to drill a more expensive hole, if it didn't have to.

The original instructions for venting the boiler can be found here
https://www.weil-mclain.com/sites/default/files/field-file/he-ii-users-manual_1.pdf Complements of Weil-Mclain.com. Proper venting is important. Even though it worked fine for 20+ years does not mean it won't fail tomorrow and you will be reading about carbon monoxide poisoning in the newspaper.

nytech28

Steve Minnich said:

Honestly, that's a mess. I'd recommend re-piping re-wiring everything from the boiler to the ceiling. 3/4" supply and return mains coming off the boiler? Unless, the boiler is 40,000 BTU or less, they're too small. The strap that's supposed to be supporting the tank, has slack in it which means it's not really supporting the tank. Pumping away from the point of no pressure change is always a good idea. The PONPC is the expansion tank. Move the pump to the supply and tie in the tank upstream of it. Use isolation flanges on the pump and install a ball valve inline with the tank. Use a Zone Valve Relay to clean up the wiring. It will activate the zone valve, the pump, and the boiler. Maybe a wash and wax too?

thanks for reading my post, yes its 3/4" supply & return, the home owner will be replacing the boiler & plans are to repipe  the system & wiring then, for know he wants to just repace the leaking valves & wait tell boiler dies.i appreciate your suggestions 

nytech28

EdTheHeaterMan said:

Explanation: Valve A is the water feed that has full house water pressure. The green arrow indicates the direction of the water flow. When it gets to a Tee the water will take the path of least resistance. By closing Valve B the water must flow towards the radiators and build up pressure in the system. If valves D, E, and F are closed. the pressure builds up in the radiators and piping with potential energy ready t force air to go down the pipes from the second and third floors. Now there is pressure on the system however the relief valve G is not seeing that pressure. Open boiler drain valve C with a hose connected to it. Now using the full house water pressure, open valve D and the water will force the air out of the pipe and radiators on that loop only.. the air will be forced into the boiler, and eventually (pretty quick in your boiler), the boiler will fill with water. Once there is no more air from valve D zone, then close valve D and open Valve E and purge that air from the radiators and pipes. Once there is no more air in zone E then close valve E and open valve F. The air from that zone will be purged and once the hose shows no air from that zone you can close valve F. Now, most of the air is all gone. Enough for the pump to circulate the water in the system. Close valve A (or set the auto-feed to the boiler static pressure (about 12 PSI). Close Valve C then open valves D, E, and F. Adjust the pressure to the desired Cold Static water pressure by adding or bleeding off water as needed. Your system is ready to be commissioned. This is only one reason to use pumping away. There are more reasons to design the piping in the exact order shown, Finally, the common pipe fro the zones should be large enough to accommodate all the zones. Use at least 1" piping to accommodate 80,000 BTU of total capacity or use 1-1/4" common pipe if you need more than 100,000 BTU of capacity If 3/4" was all that was needed for the supply and return openings the boiler would not be 1-1/2"... They would be 3/4" openings. It's cheaper to drill and tap a 3/4" hole. One thing a manufacturer would not do is to drill a more expensive hole, if it didn't have to. The original instructions for venting the boiler can be found here https://www.weil-mclain.com/sites/default/files/field-file/he-ii-users-manual_1.pdf Complements of Weil-Mclain.com. Proper venting is important. Even though it worked fine for 20+ years does not mean it won't fail tomorrow and you will be reading about carbon monoxide poisoning in the newspaper.

that was the most useful information I had in long time & very easy to follow.I really appreciate the time you toke to explain & illustrate correct way to repipe the boiler. The homeowner first wants to fix the leaking valves for know & wait tell boiler dies to replace it & i will be repipping using pumping away method if given the job. The water that was on the floor was from the leaking gatevalve that I opened & yes you can use the pictures from my job for your  class. But for know I will be replacing the leaking original valves whats your opinion ?  how should I remove the gatevalve  that's soldered to the 3/4 pipe not far from the zone valve ,am trying to not put couplings or extra fittings but sometimes unsoldering old fitting not easy any recommendations would be appreciated to do a neat clean job.

mattmia2

As for the valves, there are valves with built in unions available, that might be the way to go. I would use MPT valves and male adapters on the copper so when you rework it you can just use new pipes and adapters to the new manifold.

There are full port ball valves with a hose thread and cap attached that you could use to replace those hose bibs or you could use a manufactured purge station that has the valve that redirects the flow and a couple valves with hose thread adapters all in one assembly.