Controlling 1 pump from 2 places

[Nicik]

Hello i need help with my pump on my furnace so i need to turn it on from 2 places now it is controlled only from one place and that is the thermostat on the furnace for wood it turns on the pump when reaching some bigger temps but i also have a furnace that burns gas and it only turns on the pump that is inside of the furnace. The second pump turns on after long time and that makes a problem because on the lowest floor the heaters are completely cold so i want to wire up the second pump to the gas furnace but then it will be controlled from 2 places is that gonna be a problem ? Do i need to use some diodes ? Thanks for any help.

 

[danadak]

Probably use relays easiest approach. Depends on the controller on each
end what the interface looks like, what to use to power relays and to also
supply signaling for turning on gas furnace.

Also you have to consider fault tolerance of designs, to make sure no
failed solution breaks the safety concerns of heating system.

You might want to consult experienced heating/cooling suppliers to make
sure design takes into account all system constraints and considerations.


Regards, Dana.

 

[ahsrabrifat]

Using an SPST relay will be good. The relay coil would be powered by either the gas or wood furnace when they signal the pump to turn on. The relay contacts would then control the pump safely.

 

[Delta Prime]

You don’t need any stinking relays! Connect two thermostats to the same furnace pump, so one additional thermostat is added in the different location of your house you wish to control from.
Allowing either one of the two thermostats to trigger the pump to turn on based on which thermostat calls for the heat.
Easy Peezy lemon squeezy…
Or if you want to get fancy install motorized dampers within your ductwork this is called zoned HVAC system to control which zone receives heated air based on the thermostat signal.
Damper placement is critical so is the proper electrical connections to your furnace pump or pumps.

 

[Bluejets]

Best to draw a circuit diagram of what you intend to do.
Experience tells me there are quite often parts that are completely unthought of that will turn around and bite you.
One example could be a stacked hard wire emergency stop.

 

[hevans1944]

Wow! Is @Nicik a drive-by poster? One post on February 16, 2025 (the same day this poster joined this forum) and NOTHING since then. Not even the courtesy of acknowledging the responses received from four posters trying to answer the question: How do I control a pump from two places? I have a solution for drive-by posters: delay all responses by at least a week before making the posts visible on the thread. If the OP asks why (in a subsequent post) there have been no answers to their query, allow the first one who responded to have their post made visible on this forum. If the OP responds favorably (moderator's discretion) then allow the other posts received during the one week "time out" period to be viewed on this forum. Apply this to anyone who is posting for the first time and who has recently joined these forums.

Of course some members like to lurk here, and stay silent until they actually have something to contribute to the conversation. Don't do a posting time-out for these folks. I am often in their company.

 

[Delta Prime]

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