Very strange buzzing at gas valve

johncharles

Hi All,

This only seems to happen on days that are very cold, like last night. There is a very loud buzzing sound with an intermittent click, click sound coming from the gas valve. Jump to about 16 seconds into the video https://1drv.ms/v/s!AuWmJjPAlhDPi2gwBIxgdAFf_LhY to hear it. I spoke with the pro I have do my boiler stuff over the phone he said it sounds like it might be a "relay" going bad in the controls and will be coming out tomorrow to take a look.

But I thought I would ask here too.

johncharles

Hey, no one has replied, but I did some searching and found some similar threads:
https://forum.heatinghelp.com/discussion/152261/honeywell-gas-valve-buzzing-again

Good news, my house won't explode, but it sounds like I will need a new gas valve.

unclejohn

Did the pro try cleaning the flame sensor and pilot? Sounds like valve drops in and out.

BobC

That sounds like a chattering valve, does the noise stop if you rap it with the handle of a screwdriver?

Bob

johncharles

He's here now, he metered out the voltage and it looks good.

johncharles

He didn't clean the flame sensor, there is no pilot it has a spark ignition like a stove, but he metered out the voltage said that there was no drop in voltage and that there was a consistent call. He also tapped it, and generally fussed with it and it made no difference.

He's going to replace it, off to get parts now. He said that the electronics/controls look good given the voltage was correct.

mikeg2015

Mine is noisy sometimes too. Asked the tech I use about it, he's seen some coils buzz for years without issue. Some buzz right out of the box. Voltage checked out good. I've tapped on it, and it goes away from a while, but comes back. Sometimes it's quiet.

I can barely hear the burners, but when it's buzzing I know the boiler is running.... and the whistle through the gas meter.

BobC

If it goes away when tapped it means that something is on the edge. The coil was wound by a machine with a counter on it so it's ok. That leaves the magnetic path as a variable and that is not nearly as well set as the turns.

That valve is on the edge, it;\'s not dangerous but it's not reliable either. It could work for the next 5 years or fail next week.

Bob

johncharles

So he replaced the valve and it did not solve the problem, so he basically took each thing apart and tested it one by one, just to make sure it wasn't a sensor, he jumped out each sensor ran the boiler waited for the it to start clicking and then replaced each sensor 1 by one. He also took out and cleaned the LWCO probe just to make sure it wasn't giving false positives. None of them were the culprit. There is a slight voltage variance which he initially discounted since it was only half a volt when the clicking happens, so he put the original valve back on, and ordered a new control module he will be back today to try that.

BobC

Digital multi-meters are not very good at showing you how deep a momentary voltage did goes, the old Simpsons were better in that application. Hopefully the board is the culprit.

Bob

PeteW

I would appreciate advice on whether this problem can be caused by a bad thermostat. During the past month, the gas valve on my boiler (one pipe steam) has started buzzing about six times while the boiler was already running--and kept running. But yesterday, twice, when the thermostat called for heat, the buzzing started and the burner didn't start. The strangest part: each time I quickly lowered the target temp on the thermometer far below the room temp but it wouldn't shut off. It still read "heat on", which never happened before--it always cycles off in 10-20 seconds. I quickly pulled the face of the Honeywell thermostat off, which disconnects it, and then the buzzing stopped. The thermostat is a 5-2 day programmable one. Thinking the thermostat might have caused the previous buzzing, I put in new batteries around 2 weeks ago. Any ideas?

gerry gill

it basically comes down to the gas valves not being made in usa anymore..they used to be ironclads now we replace them like kitchen sponges.

HVACNUT

Is the thermostat new and is it 24v powered?
I know you said you put batteries in. Is there a wire connected to the C terminal though?
What model Honeywell stat and can you post a pic of the boiler wiring diagram?

PeteW

Hello HVAC NUT, Thanks for your willingness to help. The thermostat is a Honeywell 50061478-004 5/2 day programmable. Only used for my one-pipe steam system. Only two wires: red from burner control to R on the thermostat; blue from burner to W on the t.s. It is 4 years old, worked fine on my previous oil burner and was connected by a HVAC contractor to a new retrofit Beckett burner a little less than 4 years ago--has worked fine until a month ago when the buzzing started. I just changed the batteries on the t.s. that I assume are only for the clock and memory. My Amprobe meter registered 38 volts at the t.s. with the working part of the t.s. pulled off, and 38.4 volts at the burner control. With the t.s. reassembled, the DCV read 36 at the control. I had someone turn the t.s. up and the DCV went to about 1v when the burner kicked on. I suppose I could pull the wire connector away from the gas valve and see what it reads when the t.s. calls for heat. Should I?

PeteW

PS to HVACNUT -- Me again. Of course the thermostat is rated 24v. I was surprised to see 36-38 volts in the t.s. wires. Possibly a transformer problem?

PeteW

HVACNUT - I just noticed on the wiring diagram that the design voltage from the control to the thermostat is AC. When I set my Amprobe to AC, it reads 29 volts at the thermostat and control with the burner off.