Cycleguard on Smith boiler preventing radiators from heating

Dat

I have a AO Smith GB400-4L steam boiler which was installed back in 2007. As far as I can tell, all of the near boiler piping is done correctly. It is a counterflow steam system, and the steam piping is pitched properly. There are 7 radiators attached to this system, all with properly working Vent-rite radiator vents. There are no main vents on the system. I believe the boiler is sized correctly for the size of the radiators.



The problem I'm having is that the two radiators furthest from the boiler do not heat up. Like I said before, the radiator vents are not clogged. The Smith boiler has a LWCO from Cycleguard which only lets the boiler run for ten minutes, shuts the boiler down for 90 seconds, tests the water level, and then fires the boiler for another 10 minutes if the thermostat is still calling for heat.



My question is, can I remove the cycleguard LWCO and replace it with a normal LWCO that will shut the boiler off when the pressuretrol is satisfied? I'm hoping that this will allow the boiler to run longer to allow steam to reach the furthest boilers.



The other option I thought of would be to keep the Cycleguard LWCO and install some main vents, which would allow the steam to reach the furthest radiators more quickly, allowing them to heat up in the 10 minutes before the Cycleguard shuts the boiler off.



What does everyone think? Are both of these ideas bad? Suggestions?

Steamhead

Do the main vents first

that will save some energy by reducing the system's heating-up time.



Measure the length and diameter of your steam mains and we can tell you what you need.

gerry gill

Cycleguards suck.

stupidest control on the market..some engineers idea of a good thing that ultimately flops in the field..you finally get some steam up, then finally get the pipes warm, then some jerk off engineer thought it was a good idea to shut down and collapse all the steam..urrr..i replaced mine with a standard lwc.

Patrick_North

I knew it!

I had the same inkling when our new Smith boiler was installed but just assumed they knew best. But if Gerry Gill is swapping out the cyclegaurd, I'm convinced!

Anybody know if I would be voiding a warranty or anything if I had this done?

Thanks,

Patrick

Greg Maxwell

Cycleguard

Even if your cycleguard should go, it shouldnt take 10 minutes to get steam to your furthest rads. In a counterflow system, I believe that your radiator vents are your main vents. I seem to remember an old timer telling me that on counterflow, its the combined venting rate of each rad on the leg that vents that main. Check to make sure that the vents that you have are the correct ones, and the furthest vent is open the most. ( I would use an adjustable vent).

ChrisJ

Interesting

Glad to find this out now.  I was planning on replacing the standard hydrolevel LWCO with a cyclegaurd model before installing the new boiler.

Steamhead

Even on counterflow

you need main vents. 

Greg Maxwell

Main Vents

I was told that in counterflow systems, the mains could be oversized, and the radiator vents, with the furthest vent fastest, could function as main vents. DAT, do you have a place for a main vent at the end of your mains?

ChrisJ

mains

My understanding is with counterflow the mains have to be oversized because the steam is flowing against the condensate.



I don't see why the system being parallel or counterflow would matter when it comes to main vents.  The steam still needs to push all of the air out.  In fact on counter flow with the oversized main now you need to remove even more air.

Dat

Would Gorton #2's work as main vents?

The system does not have a spot for main vents, and it does not look like they were removed previously. It seems as if the system was designed to rely on the radiator vent to remove the air from the mains.



Steamhead - the boiler serves steam into a 3" header. On one side, the header travels 4', and the tee's into the 2" main, which travels 26'. On the other side, the header travels 8', and tee's into the other main, which also travels 26'. It's a small house



I have 2 Gorton #2's main vents - do you think those would be enough?



I really appreciate all the help!

Steamhead

You could try them

but if they vent those counterflow mains fast enough to cause banging, switch them to Gorton #1 vents.

crash2009

T?

 If the four foot pipe connects to a T, won't you need a main vent at each end of the twenty six foot main?  Same with the other side.

Dat

Help w/ switching from Cycleguard to Safguard LWCO

OK, it's months later and, as Jerry Gill suggested, I'm finally getting around to replacing my Hydrolevel Cycleguard CG400 with a normal LWCO. My boiler is a 24v system, so I purchased a Hydrolevel Safguard 400, in hopes that it would be an easy replacement.



My first question is, can I re-use the Cycleguard's probe with the Safguard? They look to be the same. The Cycleguard's probe does work and was inspected late October.



Next, the wiring seems to be a little different. The current Cycleguard is installed as the alternate wiring method using the plug connector in the instruction book (see link below to Cycleguard instructions). The cycleguard has terminals named 2, 1, P1, P2, A, and "burner".



http://www.hydrolevel.com/pages/pdf_files/cg400series.pdf



The problem is, the Safguard only has terminals 2, 1, P1, P2, and A - no terminal named "burner". I have tried installing the Safguard according to method C in the instructions, but the boiler will not turn on. (Link below for Safgaurd instructions). Where do I place the wire that was formerly attached to the "burner" terminal on the Cycleguard on the Safguard?



http://www.hydrolevel.com/pages/pdf_files/400series.pdf



I also have a Hydrolevel VXT automatic water feeder on this boiler, if that matters.



Any help will be appreciated - I would like to be able to get this to work without having to call a plumber, etc.



Thanks!

Dat

Went from Safguard to Cycleguard?

Thanks for the info regarding the probe, Mark. I'm just wondering, why did you decide to change your LWCO to a Cycleguard when you had a Safguard originally?

Hap_Hazzard

My radiators heat just fine.

I replaced a McDonnell Miller LWCO with a CycleGard and a VXT. The only reason some of my radiators weren't heating (after I turned down the burner that someone had cranked up to an unsafe level) was that there was no insulation on my mains, no main vents, not enough venting on some of the radiators, and too much venting on the two radiators in the living room, where the thermostat is.



Everybody likes to blame the CycleGard whenever there's something wrong with their system, but the fact is it only cuts out the burner for 90 seconds every ten minutes. The only way that could keep your radiators from heating would be if your boiler was so undersized that it ran constantly. If your thermostat is cycling, your boiler and radiators are putting out sufficient heat. If you don't like how that heat is distributed, balance your system. Put some insulation on the pipes and adjust the venting. If your system doesn't cycle on pressure, turn down the Pressuretrol. If it still doesn't cycle on pressure, and everything's heating evenly, find a new hobby. You're done.

Hap_Hazzard

Burner Lead

The "burner" lead on the CycleGard is an optional connection used to detect when the burner comes on so the ten minute timer doesn't start counting until the burner comes on, allowing the steam to fill the mains before the intermittent level test kicks in. For obvious reasons, you won't need that connection with the old-style Safgard.

ChrisJ

Cyclegaurd

I don't know,



I worked on a friends boiler which has a cyclegaurd and all I can say is I won't put one on mine. I see no reason to interrupt the burner for 90 seconds and cycle the damper motor every 10 minutes.



What I do wish I had on my safegaurd is the 'test" button. I have the cheapest model and it essentially has one LED on it.

Hap_Hazzard

I have to agree about the test button.

An on-off switch would be a good thing to have too. I got the switches to install but haven't gotten around to it yet.



BTW, I don't have a damper motor, so that's not a problem.