Isolating a zone so I don't have to drain entire system

astodolski

Hello,
I have a Burnham ES2 gas fired boiler feeding mostly convectors on a Monoflow trunk. That is one zone. The other zone feeds the Alliance indirect water heater. Both returns on each zone have their own drain and shutoff. Both returns merge to the boiler. I want to drain the heating zone. The problem is two parts. If I drain the monoflow zone, it will also drain the indirect zone because they both merge on the return back into the boiler. Second, the water feed ball valve to the boiler is to both. I can't turn on the water supply to the indirect without filling up the monoflow again. It seems I have to drain the entire boiler and not have hot water to the house while I perform the work on the monoflow. The work being performed is removal of a convector and putting in high output baseboard. I hope this was clear. If anyone wishes to help I can articulate it better if necessary.

The goal is to make the heat zone serviceable while keeping the hot water zone seperate and continuing to work.

Thanks,

Al

Jamie Hall

Three thoughts.

First, replacing bits of a monoflow system with something else is, at best, tricky, and very likely to upset the whole darn thing.

Second, bleeding a monoflow system and getting it running after draining it is also tricky.

Third, if you don't have valves which can completely isolate one system from the other on both feed and return, you're going to have to drain the whole thing. While you're at it, put the needed valves in...

STEVEusaPA

Drain the system, put valves to isolate each zone, fill the boiler and the indirect zone. Then you can spend all the time you need on your heating zone.
Make sure you check the manual for your indirect. Depending on the type, you might need to empty the domestic side, or the boiler side first.

astodolski

Jamie Hall said:

Three thoughts.

First, replacing bits of a monoflow system with something else is, at best, tricky, and very likely to upset the whole darn thing.

Second, bleeding a monoflow system and getting it running after draining it is also tricky.

Third, if you don't have valves which can completely isolate one system from the other on both feed and return, you're going to have to drain the whole thing. While you're at it, put the needed valves in...

I drained the whole system because of conditions I outlined. I replaced a convector with a high output baseboard through 3/4" PEX. The convector was fed with 1/2 inch. I bled the system completely before startup and while running. After heard no sloshing through the pipes. All heaters are HOT! Not sure how (or where) to put the valves for isolating the zone. I guess I should post pics of the system. Don't know what is meant by "upsetting whole darn thing". It is up and running as was last season. As mentioned, each zone has a shutoff and drain valve on their returns. As mentioned, I have to shut off the water supply to the boiler to drain either zone.

astodolski

STEVEusaPA said:

Drain the system, put valves to isolate each zone, fill the boiler and the indirect zone. Then you can spend all the time you need on your heating zone.
Make sure you check the manual for your indirect. Depending on the type, you might need to empty the domestic side, or the boiler side first.

I'll post pics so perhaps can get guidance on where exactly to place valves. As mentioned, there are shutoffs and drain valves on the returns