How Do I Flush And Fill Though The Mixing Valve?

[velvetfoot]

I was also going to flush the boilers, but now that I think about it, I don't know how I'm even going to fill the system. They have check valves on their supply lines and there is a Caleffi 280 mixing valve downstream on the supply header. The system auto fill valve is on the return near the tank. The air scoop and vent is also out of the loop.

Will the Caleffi prevent all flow downstream of the recirc line when the temp is cold? If so, will I have to add some drain valves and an auto fill line?

This sucks. I hadn't thought of this beofer.

 

[velvetfoot]

Here is a schematic. System auto fill valve is on return, near the tank.

 

[velvetfoot]

I am thinking (dangerous), that after I separately flush and fill the tank (water that spilled out of it from factory testing was quite red), maybe I could fill the rest of the system through the tank supply line. The tank is filled, It would then flow though the mixing valve, since it is below 130F, through the Caleffi DirtMag strainer, then through the boilers, and then where? Dead end, unless the air can escape though the Air separator (AS-1), or maybe out through the tank vent valve. Should I move the air separator? Ach.

 

[velvetfoot]

I spent some time looking at the pipes. I think for a good fill, I should add an autofill connection (and an isolation valve for each connection) to inside the loop; there's just enough room to do this. I think I could flush the boilers out without getting their pumps involved by connecting to their drains and flushing to the tank and filling and draining the tank separately (not sure of sequence). When actually filling, use the new (and old) connections.

 

[maple1]

You don't have a drain valve on the bottom of your boiler?

I filled mine through that, hooked a garden hose to it. (Had to use a washer hose in there too to get the right ends for hookups). Water in at the lowest spot possible, air out at the highest.

I filled my storage separately from another drain valve on the bottom of my tanks.

I also have a fresh fill setup higher up. It is the same one that was on my old boiler, I just moved that whole shebang to the new one. It is valved off - but if I need water in a hurry, I only need to open a valve. But if I get to needing water in a hurry, I have bigger problems to fix first.

 

[velvetfoot]

Thanks. I think I probably could do a fill through them: I figured out where I could get softened water from a garden hose tap without breaking into a line. I'll do a flush for sure through them. I'm concerned about getting too much pressure in the system, so, would have to watch the gauges for sure. I still think there might be a dead end or two if I just used the boiler drain, what with the mixing and check valves, but maybe not. In any event, now's the time to move stuff around rather when there's water in the system.

 

[velvetfoot]

Well, it seems the mixing valve caused a problem, but it'll help solve one as well. I was trying to fit in a Tee just inside the loop, next to the mixing valve, and there is no movement to sneak a Tee in there. Then, Eureka! There are union type fittings on the mixing valve and if I take it out, I'll have boo coo room.