ESBE valve + converted gravity question

gardenweasel

I am adding a bypass to my gravity converted system that came with my house. It's already 25 years old but I'm trying to keep the boiler and my 4-year-old chimney liner as happy as possible.

Was going to do a simple bypass but I got a great deal on an ESBE valve body. The piping diagram, though, looks like I need to have 2 circulators and pump it P/S in order to use on converted gravity. Am I reading this right? The ESBE instructions are hardly comprehensive.


I do worry that if I added the ESBE without P/S that the flow could be so slow through the old gravity pipes that the 3rd floor never gets warm before the thermostat on the 1st floor stops calling.

Am I overthinking this?

Zman

You need a circ on the boiler side and a circ on the system side. The drawing has a 3rd one which is unnecessary. The primary/secondary should be tied together with closely spaced tee's or a hydraulic separator.

Bill_17

Zman is correct. The ESBE diagram's 3rd circulator is shown with a dotted line around it. The full document indicates that is an alternate, but less desirable, location as compared to being installed on the outlet of the boiler.

Bill_17

See attached ESBE diagram

hot_rod

you would need to analyze the circuit. It’s possible a dongle circulator could be adequate for the boiler glue and distribution, on a direct, non primary secondary piping. There are loading units that are a pump and valve in one assembly. Commonly used on wood fired boilers