Pump not activating

[RenoTahoe]

I have a Slant-Fin system that runs hot water to baseboard system in the basement and sends hot water to "2" air handling units for upstairs heat.

The house was built in 1988 and looks like an original install. The T'stats appear to be doing what they need to do as the blowers turn on, Slant Fin is activating, but the pump does not appear to be activating. I have recently replaced the motor as it was suggested that the motor might have a bad starter switch. It is possible my issues might be stemming from something else.

I have not open up any panel on the slant fin to see how the pump is told to turn on, ie relay. Any words of advice as I look to tackle this.

Thanks

 

[WorthFlorida]

You have a hydronic heating system.

.......but the pump does not appear to be activating..........

Either the circulator pump works or doesn't. There can be a few reasons and first you need to know if the pump is turning on or not. Your system should have an expansion tank that needs to be checked so that it is not saturated and that there is no air in the circulator system. The circulator can be running but with air the system, water will not circulate. The two air handlers should have a bleed valve of sorts to purge the pipes. It might be located right at the point the hot water enters the air handler. You can google "bleed valve".

 

[Sponsor]

 

[RenoTahoe]

The pump works. Shortly after I wrote the post this morning I noticed the house warming up again. Went down and the pump was moving hot water. Its just for a few hours this morning, the pump was not turning on. To me it seems like a relay, just not sure what calls the pump to activate. The T'stat, the boiler,

 

[GrumpyPlumber]

Tstat closes the 24v circuit to the relay, in turn turns on the circulator and boiler.

My guess, when you "changed the pump motor"(assume you meant changed the circulator), you didn't flush the air out, the coils upstairs probably have auto-vents and it took time to bleed.

Either that, or the circ isn't working, but the zone is gradually heating via gravity.

.

 

[Fitter30]

Need to first check if pump has power and work back. For small pumps between just the motor vrs whole pump $20.

 

[RenoTahoe]

I did just replace the motor and did not replace the impeller side of the B&G circulator. Meaning I did not get into the water side to have air added.

Just now I hear the T’stat click on. Air starts to blow and when I go downstairs the pump is running. All is good. This morning the pump was not going. This is what is baffling to me.

I do appreciate all the responses.

 

[RenoTahoe]

Latest observation. At some point throughout the day it seems like something is keeping the pump from running. Like right now, there is a demand for heat in the house. Boiler is cycling, air is blowing, and no power being sent to the pump. Heat is rising on the pipes so I am getting some warm air but it is slow. At some point everything will start working again and the pump will go.

So, is there an aqua stat that thinks everything is fine due to the heat in the pipe and keeping the pump off or does this sound like another issue?

On each zone is an electrical box/valve with Honeywell on it. What do these do?

Thanks

 

[RenoTahoe]

Also, there is a switch box on the boiler that is essentially a light on off switch. I turned that on and off real quick and the pump activated. What is that switch for?

Thanks

 

[Fitter30]

Should be a switch for power for the boiler. Pump might be powered from the boiler. By cycling the switch it would reset any failures. Brand, complete model and serial number of boiler ill see if there's a manual with a wiring diagram on line. Take few pics of the boiler pump and zone valves.

 

[RenoTahoe]

It is a Slantfin unit but I don’t see any nameplate. Hoping pictures are attached

 

[RenoTahoe]

PDF of pics attached

 

[Fitter30]

Name plate is under the front cover might be on the sides. If its not there wouldn't doubt the installer drill right through it to mount the electric box.

 

[Fitter30]

Name plate should be under the front cover poss on the sides if not bet the installer mounted the swich box over it drilled right through it. Pic a pic of the wiring diagram back side of cover. If no diagram and a honeywell control lift cover write down complete number should end in a letter.Looked up older slant fin boiler they used. They used a lot of different controls.

 

[RenoTahoe]

Here are some more pics with the nameplate.

 

[Fitter30]

Top diagram with no vent damper has a combination control that powers the pump. Thermostat calls for heat turn pump on. Wish they showed all the safeties but it doesn't. There should be a operating and limit control. Thermostat connections call for heat 0 vac across terminals on the board. 24vac if there is no call for heat.

 

[RenoTahoe]

At this point, am I doing any harm by flipping the switch on and off to reset some switch in there?

Seems like I should install a relay to run the pump. Jump off the 24V line to a 24V coil to switch 120V over to the pump.

I am at a loss as to what more I can do. Not sure if that Honeywell controller is available for replacement.

Appreciate you answering these.

 

[Fitter30]

Take cover off honeywell control need model number will start and end with a letter or take a pic of it. These controls are used by by a lot of different manufacturers but there's probably 15 variations

 

[RenoTahoe]

I have almost convinced myself that maybe this is the way this unit has always worked. As I mentioned early on, I did have a pump motor issue. Power was being sent to the pump but the pump was not spinning. You could hear the motor trying to go. Hit the motor and it would go. I change the motor out and have not had that issue. But now that I have worked on it I was checking to make sure the motor was still good. So, as I was taking these pictures everything was working just fine. Pump was moving water. Very quiet, no gurgling. Who knows.

 

[Fitter30]

In your pic model and serial is to the left of honeywell control silver tag. There's no numbers in the pic of the control. The control is so old can't remember how the number looks.

 

[RenoTahoe]

In your pic model and serial is to the left of honeywell control silver tag. There's no numbers in the pic of the control. The control is so old can't remember how the number looks.

Serial number is 531684 and model is GG-125 HP