Intermittent water test

vhauk

Respectfully asking for some knowledge. How important does this community believe intermittent water test to be?  And should this test cycle the burner off  3 or 4 times as the boiler is coming up to steam temp?  I have a cycle guard cg-450. I’m thinking about disconnecting the intermittent test function which the literature says is optional. 

Long Beach Ed

It's more important to know and service your equipment. If the boiler is piped correctly, the water clean and not surging and the level and probe clean and maintained, I believe there's no need for a cycle testing control.

vhauk

Thanks. I’m planning on disconnecting this feature. Seems strange for the boiler to fire up and run 3 mins and shut off only to do the same thing again. I baby sat a pair of large boilers for 30 years. I think I can watch the little one in the basement. (Small in size, not in importance.)

JUGHNE

Can you post a picture of the page that shows how to prevent the Cycling?

vhauk

https://hydrolevel.com/wp-content/uploads/2008/05/ModelCG470Instructions.pdf  Best I can do as the site wouldn’t let me copy that page in question. Page 2. 

Long Beach Ed

I don't think the cycle guard feature can be disabled. It can be minimized, it seems.

vhauk

I’m goin going to find out. The manual says it’s optional 

mattmia2

there are other versions that don't do that. i suppose it is for bad installations that throw the water out of the boiler and in to the mains

Chris_L

vhauk said:

I’m goin going to find out. The manual says it’s optional 

If you are talking about the SmartCycle feature, that simply means it will restart the 15 minute timer each time the boiler starts. It will still shut down the boiler after it runs for 15 minutes to check the level.

vhauk

a according to the documentation on the Levi it’s a control scheme to prevent the boiler from running in a low water condition, if the boiler water has a problem of foaming. It interrupts the burn cycle and waits 3 mins to see if the water level is at or above the sensor. I guess there has been a foaming problem. 

vhauk

As I try to spit the taste of shoe leather from my mouth, it seems the LWCO is either miss wired or defective. I’m leaning towards miss wired. The intermittent test is only supposed to happen after the boiler water reaches boiling. But when the water temperature is below boiling there is no intermittent test. My system performs an intermittent test every 15 mins the entire burn. From a cold start. Thanks for all your help and patience. 

SteamingatMohawk

I searched on CG-450 and got the manual for the CG-470 series. It appears there is a difference between the two, namely the manual for the 450 does not have the boiling discussion. I don't know if/when the model changed, but here is a link to the 450 manual.

https://hydrolevel.com/wp-content/uploads/2022/03/CG450-CGT450-Instructions-012422.pdf

Here is the link for the 470, which has the boiling discussion.

https://hydrolevel.com/wp-content/uploads/2008/05/ModelCG470Instructions.pdf

I have a CG-400 (24 volt). My understanding is the default intermittent level test operates every 10, 15 or 20 minutes depending on the model number last four digits as long as the boiler has power, regardless of whether or not it is firing. The Smart Cycle changes that to starting the countdown when the boiler starts. All that does is prevent the test from occurring until that amount of time, whereas the default timing for the first test would occur at the remaining time left in the cycle. So it's possible the test could occur anywhere from 10 minutes to 1 second after the boiler fires. After the first cycle the full time occurs between tests.

I like it for my situation, because it helps keep boiler pressure down by shutting off the flame every 10 minutes. Some of the guys on HH don't like it for a variety or reasons. One dislike is too many cycles on the gas valve and damper.

Make sure you are looking at the exactly correct manual. Good luck.

JUGHNE

I see they added an over temp feature.
Also the clock will not start until you get to boiling temp.

That is an improvement from previous.

However is the high temp limit a one time shot, the manual says you should replace the control if it has hit high temp (250 degrees)?

The ones I had, the clock was counting 24/7.
You might fire up perhaps 2 minutes before the check was to be done.
Just get started then shut down.
The vent damper stayed open, upon restart the damper had to cycle to off and then cycle to open.

If there was a delay from the tstat to start that added more off time.
Sometimes all this would stop steam production enough that the air vents might open.

They were removed and the non cycling LWCO replaced them. My systems work much better.

Plus there was a second (manual reset) LWCO required for these boilers.

Somewhere there is a pile of Cyclegards that were pulled out and shelved if you need a new one.

Some here like them.

SteamingatMohawk

I'm interested in what exactly is the difference in performance? Mine stays off for 90 seconds plus whatever other delays are built into the system. I can't imagine it makes a substantial difference, unless you are also considering the temperature function to be a substantial difference. Mine doesn't have that.

I also have to mention, my system is in an old two family, typical in the area.

JUGHNE

In my case I have 100' of 4" main with another 40' of return to the air vents.

There are only 4 radiators on this, 2 on 15' risers.

So we have a lot of pipe to heat up before the rads do.

Boiler is oversized to account for pick up of large pipe.

vhauk

Very interesting guys. I’ve learned a lot. We’ve changed our one pipe system from 9 radiators to 5. Derated the burner and have the system working pretty good. But when we would get a call for the burner it would cycle off sometimes in a minute or so after starting the burn. I’m thinking that I might just replace the CG-450 with a 460. Thank you all for the fun. 

BobC

It sounds like Hydrolevel listened to the complaints about the original CycleGard and did something about it by allowing people to decide haw they want their boiler to operate.

Bob

SteamingatMohawk

vhauk Have you determined whether or not your unit is installed and functioning as designed?

vhauk

You mean the LWCO or the entire steam system?  I believe the LWCO is working as designed. We have changed the steam system a lot. I have a new main vent that I need to install but everything else seems to work good. I started this because the boiler was cycling early in the run to boiling, and I was trying to find out why. Checked pressure trol, which was set to 8 psi. It’s at 2 now, thank you. Installed 1-3psi gauge and now know it’s not pressure. 

SteamingatMohawk

I am referring to your concern about miswiring or malfunction of the LWCO, since the information I found on the 450 has two different manuals.

As far as the system is concerned, lower pressuretrol setting is better. Be careful, sometimes they are finicky in the lower range. Other HHers can explain better than I can.

Your previous experience may or may not be helpful as the operating conditions are very different, especially those systems that were installed in the earlier days of residential steam heat.

From a code point of view, the 30 psig gauge is required (lots of comments about that on HH) and if you leave your low pressure gauge installed, it should have an isolation valve so it won't see a pressure excursion when it is not in use. Only have your low pressure gauge on line when you are present. Lots of suggestions on that too.

One recommendation is a Magnahelic, which can withstand boiler pressure up to the relief valve setpoint.

vhauk

the I’ve come to believe that the LWCO is working properly. Or, as designed. I’ve ordered a 550p and hope that will work better. I look at the boiler every day that it fires. Closely. I can hear it firing from in the house. I didn’t know about the gauge pressure code. I replaced the 0 - 30 psi gauge with a 0 - 3 gauge. The system as configured never moves the needle off 0 psi. But the isolation valve for the gauge makes a lot of sense so that’s happening too. Thank you very much for sharing your knowledge. 

ethicalpaul

Well they kind of can...see my latest video: https://youtu.be/yEJi2uliCs8