Boiler circulator question??

[BarryinMN]

I have an old Montgomery Wards propane boiler system with 2 zones, 1 up and 1 down.

I noticed the circulator pump only runs when the burners are fired.

The circulator should run independent of the burners right?

The two water zone valves have 4 wires each out of them 2 red and 2 yellow.

Anybody help with a wiring diagram of this?

Also any advise on a modern centralized air removal valve, it appears that thumb screw valves on each baseboard heater were removed.

Thanks

 

[beenthere]

I think the burner only runs when the circulator pump starts as a result of a thermostat calling for heat.

I used to have an oil-fired system that would just maintain the water temp at like 180°, and the pumps would run when heat was needed. Now I have a gas boiler, and it operates when the pumps run AND the water temp is below a set point. That means the gas isn't heating water if no heat is needed in the house.

When my system was put in, there were no air bleed valves in the system. Depended on blowing water through the pipes to force out any air in the system. Took some doing to get it all out. When I re-worked the system, I added air release valves, but still have a few spots that can get air trapped. The system doesn't work well if there is air in the lines.

 

[robison]

Modern systems have a loop of pipe going out of the boiler and back into the return. That loop has a circulating pump. Tapped into that loop you have the loops that heat the house, each with its own pump.

The system you have sounds like you have a Y coming out of the boiler, two circulators, and another Y to return the water to the boiler.

In both cases you do not want the boiler to run unless the circulators (one or both) are on.

 

[kenmac]

It all depends on how your unit was wired in when it was installed . I can tell you that most boilers I have worked on,The t.stat calls for heat the pump starts to run which makes up a flow switch to (ensure that water is circulating through the unit) which may go through several other safety switches on the unit & then sends power to the gas control to fire the boiler. /forums/images/graemlins/wink.gif

 

[Egon]

On our hot water heating system/domestic supply system the circulating pump does not come on till a certain water temperature is reached for the heating system. I've check this with a voltmeter. Probably a function of the dual use furnace.

Egon /forums/images/graemlins/grin.gif

 

[kenmac]

That's why I said , it all depends on how it was wired to operate when it was installed.There is no set way to install a system.It all depends on the boiler .It may not operate with a flow switch.in which case the motor woundn't have to come on b-4 the burner fires.

 

[beenthere]

No Y in my system.

Like I said, my old oil boiler just heated water and kept that water hot (kicked off at the upper limit, and kicked on at a lower limit), very similar to the domestic hot water heater (just keeps the water hot). The three circulator pumps were independent of the oil boiler unit, and just circulated hot water when the thermostat in each of three locations in the house would call for heat. Didn't make any difference if there was hot water to circulate or not, the pumps ran if the temp was below set point.

I have one pipe going out of the boiler (s) to a distribution manifold for the three circuits, and the circulating pumps are on the return lines from these three runs. From the pumps, the return water either is directed to the gas boiler, or the wood boiler.


That (old oil boiler) is how my wood boiler system works now. I maintain a fire to keep the water hot. If any of the three circuits in the house demand heat, then the pumps get kicked on and water going through the wood boiler is circulated regardless of the temperature of the wood-heated water. If the wood fire goes out, the house can get cold as the pumps just circulate cold water. Helps when (if) the temps drop below freezing, as at least circulating water will not freeze up as quick.