Using a Taco 0018e for panel radiator loops

hotsauce

I am adding panel radiators to a 90's era home that originally was heated by electric radiant ceiling. I have a manj and am planning on two loops using the Taco 0018e as the circulator and relying on the TRV's on each panel to regulate temps. My general question is how to start and stop the 0018e circulator when all of the TRV's are closed? Will the proportional differential mode of the 0018e stop the motor when there is no flow and then start it up again when one of the TRV's opens again?? Or do I have to use some form of external control, like a ZVC controller? Trying to keep the circuit complexity down! TIA for any advice!

Dave H_2

How do plan on telling the boiler to turn on?

You have two ways;

1. The boiler, if it has contacts to turn on/off a circ and the boiler turns on/off/modulates based upon outside temperature. You can put the circulator in the proportional pressure mode and it would modulate down to 4 watts and barely spin when the TRV's are fully closed.

2. A thermostat in the house to signal on the boiler and the circ. You can use a Switching Relay like the SR501 that can interface the boiler, thermostat and the circ. Pretty reliable and simple to do.

When is a circulator and a boiler most efficient?

hotsauce

Dave H_2 said:

How do plan on telling the boiler to turn on?

You have two ways;

1. The boiler, if it has contacts to turn on/off a circ and the boiler turns on/off/modulates based upon outside temperature. You can put the circulator in the proportional pressure mode and it would modulate down to 4 watts and barely spin when the TRV's are fully closed.

2. A thermostat in the house to signal on the boiler and the circ. You can use a Switching Relay like the SR501 that can interface the boiler, thermostat and the circ. Pretty reliable and simple to do.

When is a circulator and a boiler most efficient?

Thanks David! Sorry I wasn't clear. I am not worried about cycling the boiler. Mine is a Navien modcon and I am controlling it from a thermostatic switch in the buffer tank. What I hope to do is figure out how to start and stop the 0018e circulator without having to resort to a ZVC controller. Each panel radiator has its own TRV.

Dave H_2

No worries, I understand. I see that the buffer tank will control the boiler, but what about during the summer?
Will the buffer tank be kept warm?

The most efficient circulator and boiler are the ones that are off! They use no electricity nor burn any fuel in the off position.
So sequence of operation;
1. It is cold outside
2. Sensor on boiler puts boiler on standby (don't do anything but wait for a signal)
3. Thermostat in house drops below setpoint
4. closes contact in stat which in turn will signal the Switching relay (SR501).
5. Switching Relay in turn will tell the circulator to turn on
6. at the same time as circulator is energized, a signal will go to the boiler to make heat.
7. Boiler fires until sensor in buffer tank is satisfied or thermostat is satisfied (whichever is first)

Thermostat location and setting is important here.

hotsauce

The real issue here is there are no thermostats! There are only TRV'S. I have never relied on TRV's before... all my experience is with thermostats. So with TRV's as the only temperature control in the system how do you control the 0018e circulator pump? Something has to turn the pump on when there is demand for heat and turn it off when the demand has been satisfied!

hot_rod

A circ in delta P mode will ramp up whenever a TRV starts to crack open, you should not need any other interface for circulation. When all TRVs are closed it should go to idle mode. The boiler fire is based on a buffer tank call?

If not a low flow type of flow switch near the circ could trigger the heat call to the boiler. But I assume you want to maintain the buffer tank all heating season?

Dave H_2

If you have that thermostatic switch turning on and off, there is probably a RIB relay that can work for you to switch on and off the 120V side of the circ

Enjoy

EdTheHeaterMan

@hotsauce Is indicating that there is no 24 Volt room thermostat. I don't believe that adding a room thermostat occurred to him. There is no need for a thermostat since all the radiators have TRVs. Unless of course, you want to maybe add a 24 Volt room thermostat in a random room that will be able to provide the sequence of operation @ @Dave H_2 described above.

But where to put such a device in a home with no thermostat. Some research on what room is the hardest to heat might help to locate the best place for the thermostat. Or maybe use the Rh and W on a cooling system thermostat that is already there. So many choices, what is the best one?

Trial and error come to mind.

Mr.Ed