Riello series 40 F5 motor short cycles never locks out

jpnova70

Crazy issue with my F5 .When motor starts it short cycles roughly 4 seconds when calling for about 5 times then runs fine. Never locks out although sometime cuts out mid fire 1 minute in. Filter and pump screen cleaned and replaced.Electrodes, nozlle and control were replaced already. Is the motor on it`s way out possibly or cap? Tstat is calling.

STEVEusaPA

Burner on what furnace/boiler?
Sounds like loose wiring, maybe in the tstat or control base.
What do you mean short cycles? Completely shuts off, starting/stopping?
I'd disconnect the power, remove the primary control, check all the wiring, making sure nothing is loose on the base, make sure all pins are getting good contact.
If it still happens, I'd jump out the thermostat to eliminate that and continue troubleshooting with my meter. Where is the tstat connected-into the control, into a board or aquastat?
What other components on the system, i.e board for the furnace, aquastat for boiler, zone controls etc.
Tech should've done some troubleshooting before replacing the electrodes and the control box. I've only replaced one set of electrodes in almost 30 years, on a Riello, and that's because I broke them, dropping the assembly.
Riello has a simple troubleshooting guide to walk a tech thru to check all components with a meter.

EdTheHeaterMan

Riello sequence of operation is somewhat unique, whereas,
on a call for the burner to operate, L1 and Common are energizes with 115V AC @ 60 hertz. Once that happens the motor operates. The back EMF (electromotive force) of the motor operation is the power used to power up the electronics of the primary control. This means the control is not the issue. The power supplied to the Burner is where the fault is. If the motor is stopping and starting it is because of a loose connection or other interruption in the 115V. feeding the burner where indicated below.

EdTheHeaterMan

If you have power here the motor should operate. if you don't have power here the motor should stop. SOOooo if you have power here and the motor stops and starts and the power here is not interrupted. The wires from here to the motor windings are loose or defective... replace the motor.

If the power interrupts every time the motor stops... the burner is fine. check elsewhere.

HVACNUT

It sounds like you have the electric air gate on your F5. The end switch is not making, and round and round the damper she goes.

I wouldn't bother replacing it as Riello doesn't ship with an air damper equipped anymore. The other style, and more common is the hydraulic air gate.

There is a way to eliminate it. I have the diagram at home and will try to post later.

Any route you go, a technician must adjust/check new air adjustments, and lock it.
A combustion analysis and smoke test as well.

In the meantime, a soft Sriker kick on the right side of the Riello cover might teach it a lesson.

jpnova70

Thank you all for your input this is valuable information I will come back with my findings tomorrow morning thank you all again

jpnova70

All fixed after following this comment.
Here's what I wrote up for my guys.
Turn off the power and remove the primary control.
Where the power comes into the burner sub-base, you will see a black wire, that comes from the damper, attached to the constant power wire, maybe red in color. Remove the black wire and retighten the screw.

Remove the white wire, that comes from the damper, from screw number 3 and retighten the screw.

Remove the black wire, that comes from the damper, from screw #6.

Remove the black wire, that comes from the damper, that connects with the blue wire and connect the blue wire to #6. Retighten all screws.

With your right hand, take the damper and slam it into the trash can as hard as possibly. I highly recommend, when you find one of these dampers on a cleaning or service call, that you remove it because it will fail and result in a no heat call.

EdTheHeaterMan

@HVACNUT
I forgot about those electric dampers and end switches. I have the old Riello with the piston. You may have nailed it!

HVACNUT

@jpnova70 for what its worth.

Yeah, the electric air gate goes to the land fill. But the upside is that by not having the hydraulic jack, you probably saved yourself an oil leak.

jpnova70

Perfect thanks

jpnova70

So just to follow up I decided to replace the electronic damper motor. As I removed it I found a piece of solder wedged in between the gears seem like it came out of the motor itself. 15 year lifespan

HVACNUT

Riello used to outsource to Cogswell Cogs. Now their gears are supplied by Spacely's Space Sprockets so you should be good.

Mike M

Huba-duba-doo

HVACNUT

> @Mike M said:
> Huba-duba-doo

Do you mean "yabba dabba doo"? Wrong millennium.

jpnova70

Quick question boiler shows 20 psi but leaking buy at a 180ﾟ expansion tank PRV and make up Valve all replaced less than a year ago. Prv bad already? Lowered limit to 175 okay for now

SuperTech

> @jpnova70 said:
> Quick question boiler shows 20 psi but leaking buy at a 180ﾟ expansion tank PRV and make up Valve all replaced less than a year ago. Prv bad already? Lowered limit to 175 okay for now

Make sure that the gauge is accurate. I would also remove the expansion tank and check the air charge in it. It should be around 12-15 psi. Also the the water pressure in the boiler should be 12-15 psi when cold for a two story home. Could be a piping issue. Are you pumping away from the expansion tank? Pumping into the tank is an easy way to destroy the diaphragm.

jpnova70

Yes pumping away from the tank it is a 2 story home with all pex piping for 2nd floor extension. Zone valve was just replaced but that shouldn't have any effect. I will check the pressure in the expansion tank and verify guage.

HVACNUT

What are you using for DHW?
Could be a pin hole in a HX?

Just to clarify, because I'm easily confused, a PRV is the pressure reducing valve. The boiler relief valve is just that. A 30 psi (water) relief valve. A domestic relief valve is a T&P. Temperature and pressure.

jpnova70

Using an inspection mirror found no leaks in HX that I could see anyway although when turning the cold water on at only one sink seems there is air in the beginning after fsucet has been off for while this is a city water supply could be just the faucet because nothing else in the house does that. Still not convinced that job pressure relief valve is not faulty.

HVACNUT

Put a bucket under the discharge pipe.
Pop the lever on the relief valve to test and re seat.
Set a dry bucket there and keep an eye out.

SuperTech

> @HVACNUT said:
> Put a bucket under the discharge pipe.
> Pop the lever on the relief valve to test and re seat.
> Set a dry bucket there and keep an eye out.

Just have an extra pressure relief valve on hand when you do this. Be prepared to replace it. Pressure relief valves should be tested annually to ensure that they are functional. They are a very important safety device! I would raise the boiler pressure up to 30 psi to ensure that it opens when it should. The problem is that when it closes the valve usually drips afterwards and requires replacement.

jpnova70

Bucket was there when testing prv. Problem is I don't trust the gauge. Goes off at 21 psi per Tridicator

SuperTech

Tridicator could be stuck, or just off. I've seen quite a few that still read pressure after I drain the boiler. I've also seen a bunch that read incorrectly because someone over tightened it by screwing it in by hand without using a wrench until they can no longer turn it by manually grabbing and spinning the gauge.

dav

Probably air in the system.