Aquastat relay type l8148e manual

If you see burn marks like this don't bother with costly diagnostics. If there is no obvious visual evidence of a burn-up nor smell of burned electrical components, the heating system and possibly even the control still needs diagnostic service and repair.

While you listen at and look at the aquastat, have an accomplice turn all of your thermostats all the way up. You should hear a "click" at the aquastat and if you were watching closely, the aquastat relay switch may have "closed" by clicking "down" to turn on the circulator pump s. Check at your electrical panel for the fuse or circuit breaker powering your heating system - be sure that electrical power is on.

If in doubt, switch the breaker fully to OFF position then turn it back on, or replace the fuse if it's a fuse pane with a new one. Watch out : do not remove the panel or fuse box cover and don't stick a finger or any tool inside the electrical panel as you could be shocked or killed.

Call your heating service company. However a service technician might elect to try some of the following steps to be sure that her diagnosis of a bad Aquastat L is the right guess.

And check that and that room temperature is below the set temp in the thermostat. I turn the TTs all the way up - and leave my truck keys atop one of them so I don't forget to set them back to the homeowner setting before I leave.

If there is no voltage supplied to the aquastat then the problem begins at the electrical panel - blown fuse, tripped breaker, or in a wiring short or disconnect between the electrical panel and the electrical box powering the aquastat and heating boiler or furnace. If there is voltage then let's be sure the thermostat's call for heat shows up at the Aquastat. On the Honeywell LE Aquastat used to control separate, multiple zone valves or zone circulator relay switches the two thermostat wires will be connected to terminals marked T and TV.

If you need to rule out the thermostat itself as the problem, simply remove the wall thermostat and jump or tie together the two heat wires - usually red and white - to call for heat. This is the same as turning the thermostat all the way up.

Watch out : Before leaving the job don't forget to restore the thermostat wires to the terminals wherever you've disconnected them. If you've ruled out a problem at the thermostat itself and at the thermostat wires, continue below.

On a call for heat the relay switch should click and should "close" or be in the "down" position on the circuit board. Watch out : I have seen techs just push down the relay to confirm that voltage is then produced and the circulator pump runs, but if the thermostat is calling for heat and the relay doesn't close on its own then either the control board or the relay is bad.

Watch out : there is live voltage here. You can be shocked or killed. If the relay closes as it should and there is voltage at the circulator terminals then the problem is downstream from the aquastat. If the heating system uses multiple zones each will be controlled by a zone valve that opens or closes a loop of heating water pipe and that turns a common circulator pump on.

OR each zone may be controlled by individual heating zone circulator pumps that are in turn switched on or off by a separate heating zone circulator relay control. When a thermostat controlling an individual heating zone calls for heat in this design either an end switch on the zone valve OR a relay switch in the circulator relay turns on the circulator for that zone.

At the zone valve or at the circulator relay control check the thermostat terminals for 24VAC at that control and check line voltage at the common circulator or at the line voltage terminals in the circulator relay if one is used. On a zone valve system if the zone valve doesn't operate when there is voltage across the thermostat wire terminals 24VAC at the zone valve, then the problem is at the valve - the control head itself, or the actual hot water line valve could be jammed.

If there's no voltage at the TT terminals on the zone valve then we're back to diagnosing the thermostat itself or the thermostat wires or the low voltage transformer - topics we listed earlier. On a multiple circulator system if the circulator relay doesn't close when there is voltage across the thermostat wire terminals 24VAC at the circulator relay, then the problem is a bad relay or relay control board. If the circulator relay closes and produces line voltage at the circulator terminals C1 C2 in the relay, but the circulator doesn't run then the problem is in the circulator or circulator power circuit.

When the thermostat is calling for heat the burner will nevertheless remain OFF until the boiler temperature falls to or below the CUT-IN temperature on the limit control on the Aquastat typically 15 deg. Green in our edited version of Honeywell's drawing. IF voltage is being supplied to the burner to turn it on and the burner never runs, the the problem is probably not the aquastat but the burner itself, such as a burner that has tripped off a cad cell relay or other safety control.

On - by mod - buzzing noise cured by replacing the aquastat. Don Having replaced the aquastat and noting that the noise has stopped sounds reasonable and might well confirm our guess at a bad aquastat relay. Better to fix a problem like this before it fails hard and leaves your building with no heat in freezing weather. While it's technically possible to do so, we will virtually never find a heating service tech trying to replace just the relay on the control board of a failed HVAC control; the time and trouble and risks just don't add up for the service company; it's quicker and easier to replace the whole control.

On by Don Hardcastle. Don Hardcastle, they replaced the Aquastat, even though it was new, and the noise seems to have disappeared. Don Hardcastle, A buzzing aquastat is usually a failing relay or on occasion a failing low voltage transformer. That's disappointing on a new aquastat - so check for a bad transformer first. On by Don Hardcastle - plumbing company wants to replace the White Rodgers zone valves with Honeywell zone valves.

My Aquastat LA sometimes makes a loud humming type sound. It appears to be coming from the switch relay. When I push the relay the noise stops. They think that is the solution to the noise. The noise occurs when any of the 4 zone valves comes on. One of the zone valves is only a couple of months old.

The Aquastat is only a couple months old also. MICHAEL, sometimes when you have a known good gas valve but the pilot won't stay lit, AND if you're sure the pilot assembly is also new and good, And the problem is that the sensor is not placed properly and the flame or That the other end of the thermocouple is not fully seated in the gas valve.

I've been fooled on this myself a couple of times. I found if I didn't screw the little fitting sufficiently tightly into the bottom of the gas valve the pilot never opened the valve. I have a slant fin hot water furnace. I have had continued issues with my pilot going out. I replaced the honeywell thermocouple on a number of occasions with an additional honeywell brand thermocouple.

When the burner does run the gas flame height is normal and the gas pressure appears good. I then assumed it was the pilot mechanism in a defective gas valve that was the problem. I replaced the gas valve with a new valve. The pilot light continues to go out periodically. It is a mystery. Can I rule out any connection between the pilot failing and the aquastat control for the burner? Ken, Nice; I'd like to see the diagram; you can use the "Add Image" button if you want to try posting that.

Lc I can only guess with just a tiny bit of information in your note but it's possible that your aquastat relay has burned contact super that the relay itself has failed. If after checking all of the electrical connections to be sure there's nothing simple like a loose wire, or a bad thermostat, you may have to replace the relay or the control itself. I have an honeywell aquastat relay le and the relay switch won't turn on the ignitor.

I have to click it and then it turns the ignitor on. What can I do to fix the problem? I have a resideo Lj which is replacing a Honeywell aquastat. I have wired it in and can not get the contactor switch to pull in or burner to light. Most technicians just replace the control entirely rather than attempting a field repair. I think they figured that they had a labor and the risk of an unsuccessful repair calculate out to that conclusion.

Is it better to replace the whole circular relay or can i do it peice by peice and wich would be cheaper. My boiler is controlled by the LE model Aquastat which has a 2-wire control up to an old "not-so-smart" digital thermostat that runs on 2 AA batteries.

All of the smart thermostats require a C-wire. Since there is no terminal on the Aquastat labeled Common, How or where do I run the new wire from? Watch out: if you are not familiar with safe and proper electrical wiring you could get shocked or start a fire. I jut wired it based on the one I removed. Same red wires with black spots on the one that had been running for years.

Crystal: Watch out : I see burned wires at the top of your controls, those two red wires. Those wires are connected to what are supposed to be the Thermostat terminals, normally low-voltage 24VAC - so I think something's wrong here. Who wired this up for you? Hi everyone, I just installed a new AquatatLJ on my boiler along with a new expansion tank, pressure relieve valve nut and automatic pressure vent and I can't get heat.

The boiler turns on, the water heats up but I can't get it to send out the water when the thermostats call for it. I have 2 zones with separate thermostats and it isn't working for either so I am fairly sure it is not the thermostats or the zone valves causing the problem.

I labeled all my wires and rewired it based on the labels but I am wondering if I messed up. I am thinking it is the T and TV connections that would be causing this particular issue but I don't know enough about it to be sure.

For fun both wires are red so its difficult to tell which is which and they both lead out to red wires on the zone valve motor boxes. The relay doesn't engage when the thermostat is turned on, and if I manually press the relay the pump seems to come on so I think that rules out the pump as the issue either.

Side note, the replacement was technically LJ and my original one did not have on the model number but they looked exactly alike so I was guessing they updated the model number in the decades since the original was installed. Thanks for any help you can give, its getting cold tonight :. Ed First check the settings in your control to be sure that your high limit is set below degrees.

Make sure that the low limit is at least 20 degrees lower than that. If the settings are correct then I suspect either that the sensor in the sensor well is not correctly sensing boiler temperature or has failed, or the control itself has failed.

Those are repairs that can be done by your heating service tech. I have an aquastat LE and when I call for heat it fires up and when it reaches set temperature the circulator pumps keep running and the temp just keeps rising until I have to turn the power switch off because it gets like a sauna? Please help. Watch out : if you are not trained on safe and proper electrical wiring you could be shocked or killed or could damage the equipment or cause a fire. Also the line feeds from a transformer, to gas valve, to LA thermostat then to the hi limit LC.

If the relay won't pull in when voltage is applied to the terminals then it is probably defective unusual in new equipment Check first for a wiring error. Travis I suspect the problem is in a connection or wire right on the aquastat control board or relay.

I'm assuming that you've checked or can check that - the supply voltage to your building is around VAC at the same time that you are seeing 90VAC at the aquastat B1 B2 burner terminals - there is no problem with under-sized wiring. Largely, my aquastat seems to be operating in accordance with what is described above, but for the fact that I get a 90 VAC reading between B1 and B2.

The conclusion is there is some voltage drop I assume is not enough to fire the boiler Can anyone confirm? Any ideas what would be causing the voltage drop? Thanks for the follow-up; do keep us posted.

Yes it's disappointing that as business models shift to very high volumes customer service is on the wane. Thanks for the prompt reply Dan. External connections and internal schematic for LA. Aquastat LA Accessories pdf manual download.

Show More. Wiring LE with internal plug directly to vent damper in hydronic intermittent pilot system. If so bad relay, or loose wiring terminals on the board. This control has built in transformer that can burn out, that will stop the pump relay contacts from working. Absolutely with you it agree. In it something is also to me your idea is pleasant. I suggest to take out for the general discussion.