cycleguard lwco + 2-pipe vapor

Garret

Thanks, Charlie.

From some searching around, it looks like Hydrolevel added the -2060 model (test 60 secs every 20 minutes) so there would be an option with longer runtimes...

My boiler's water level is very stable, so I'm thinking the "90 seconds every 10 minutes" is excessive. It seems my boiler is either heating water back up to the steaming temp, or shutting off to test the level, half the time. It only gets in a groove and makes steady steam for 5 minute stretches.

I also have a new float-type LWCO... I wonder if I could disable the Cycleguard for a while as a test. Hmm...

Garret

I have a Peerless 61 steamer on a 1923 2-pipe vapor system. You guys helped me during the upgrade process a few years back.

The new boiler came with a Cycleguard probe-type LWCO, as well as a standard float type. We have a honeywell mercury vaporstat.

I added a low pressure gauge before the heating season so I could obsessively monitor how my system is working, and try to improve things for better efficiency. (Yes, I have steam on the brain.)

During a long call for heat by the thermostat, the boiler manages to build very little pressure, maybe 4oz, before it has to shut down for the Cycleguard "90 seconds every 10 minutes" test. During the test, the pressure drops quickly to atmospheric pressure. After it restarts, it takes another 2-3 minutes to show pressure on the gauge.

I can't imaging these little cycles are good for my overall system efficiency.

A few questions....

1) Am I right that on a two-pipe vapor system, where the return side is open to the atmosphere.. it's very hard to build pressure. You have to heat every radiator all the way across, and close every trap... So the low pressures I'm seeing are normal?

2) If I never build any pressure, what's the point of the vaporstat? It was a pricey upgrade, and I expected it to do something useful.

3) Do you guys recommend I have the cycleguard LWCO removed or replaced with something else that does not shut down the boiler so much? We have the Hydrolevel CG400-1090. I'm wondering if we should use the CG400-2060 instead, which would only shut down the boiler 5% of the time instead of 15%.

I've compared power bills from before the boiler replacement and after, correcting for HDD, and we're only saving 10% gas usage. So I'm suspicious about these frequent short cycles.

Jamie Hall

1 and 2

I can comment on -- yes, on a vapour system it's hard to build up pressure. But who needs it? If the steam is getting to the radiators, that's what counts! Half an ounce or less should do it. However,

Two -- when the radiators are pretty well filled, which they will at the end of a recovery or something of the sort, you definetly want the boiler to shut off somewhere below say 12 ounces. Otherwise not so good things happen! Hence the vapourstat. In the bad old days, the system never did build pressure, as the automatic damper on the coal furnace modulated the fire.

Garret

Thanks for the quick reply, Jamie. I know I don't want pressure.. I'm just trying to figure out how to balance that against the other reality of not wanting short cycles.

Even at the end of a deep recovery, the boiler has at most 4oz. And as soon as the cycleguard test kicks in, it's 0.

Right now the vaporstat is set to cut out at 8oz, and cut in at 2oz. It never cuts out... I think I got it to cut out when I lowered it to 3oz.. but then it had trouble cutting back in and we woke up to a cold house. I think I've read here that these controls can act up when you set them that low.

Charlie from wmass

I have a customer who has a HBsmith I installed and the unit has the same LWCO on it. I have found the system does not build much pressure and some rads do not heat all the way across. the thing is they had a dramatic drop in their gas bill and the house heats very evenly. Every room even in this weather is within a degree of each other. The system simply shuts off on temp more than on pressure. I find the shutdown to be quite annoying. The customer does not as they accept its purpose.

Garret

bump...

Does anyone else have an opinion on this?

On two-pipe steam installs, do you typically install a probe-type LWCO with 10min/90sec test cycles? Or do you prefer a float-type LWCO, or a probe-type LWCO with no test cycle (or a less frequent & shorter test cycle).

Could this be why I'm not saving much on my gas usage compared to my old cast iron beast? The old boiler ran for long cycles... sometimes 45 minutes straight during the coldest weather... this new one never makes steam for more than 5-7 minutes at a time.

Thank you all!
-Garret

Garret_9

one last bump...

sorry for the extra bumps...

Do you all think it would be advisable to switch to a probe-type cutoff with no test cycle, or to one with a 20 minute test cycle?

-Garret

Charlie from wmass

Garret the lwco test cycle is a good idea if you have the float type already installed and you are comfortable in temporaially pulling the cycle guard out for a test run then try it for a week. I would be concerned if the unit was not going to be watched for that time as there is no point in messing with it if it is heating the home evenly. insulating pipes checking for leaking steam vents and what not may help you realize the savings you are looking for. The warranty may require the cycle guard though. It is a lot of money to spend for the other cycle guard if the manufactures tech dept can not give you an answer to fuel savings. Tekmar has a control the D269 that may help but not sure the savings will be worth the investment.

Unknown

Just installed a steamer

with the CycleGuard yesterday . Although I do like the idea of shutting the burner down periodically to test the true water level , I'd rather have 2 probe LWCOs without that feature . Or at least have the capability to widen the cycle time .

Garret_9

Thanks, guys..

I also like the idea of the test cycle... of course I don't want to dry fire the boiler... But this is a two pipe vapor system that fills all rads on 2 ounces of pressure, and pretty much doesn't lose a drop of water. We also have a new M&M 67... which I blow down weekly. The PH is okay so it doesn't seem to foam... Everything looks perfect to me except these forced short cycles.

Is everyone shipping their steam boilers with these "test cycle" probe-type LWCO? It seems to be a peerless preference, for sure...

Hmm.

Cheers,
-Garret

Charlie from wmass

ROn I agree I was hoping it to be field programable. even perhaps a few micro switches for choosing what suits the system. as in if there are great returns then allow a longer run between tests or if return piping is not so good then test on the basic schedule.

Garret_9

yah.. I have an email into Hydrolevel to ask if the controls can be adjusted.. but also no response.

I think it might be time to have an electronics engineer friend of mine take a look inside. Can't be very complicated in there...

... but then the warranty issues.

danl

same problem with short cycle time on CycleGuard

I have a very similar system and I believe I have the same problem with the CycleGuard. My 1931 boiler was originally coal fired. I recently upgraded to a new oil fired boiler with a Cycle Guard which stops the cycle every 10 minutes to check the water level. Seems that the radiators at the end of the loop don't get warm. I figure the original boiler was meant to go on in October and off in April so my theory that if the cycle ran 30 minutes or an hour, all of my radiators would get hot.



Am I on the right track? Can I configure the CycleGuard? I looked inside and it seems all solid state. Do I need to just get a different low water monitor?