Invest in vaporstat?

malex

I have gotten my circa '37 1 pipe system to run pretty well thanks to the tips from all the good folks posting on this site. I have insulated mains (and risers as far as I could reach) and decently vented mains - two G2s on 45' main and G1 on 12' main (NBC would probably say poorly vented :)). Gortons of different sizes on all rads. Boiler is pretty well matched to the EDR, maybe a tad bit large as I have a hot water loop that is mostly turned low. Skimmed the system for hours last year and this year and the Ph looks OK (slightly low at 6 to 7 - who bought the last Steamaster tablets from Amazon?!)



Now to the issue: I keep the temp steady at 69 on my FocusPro and rads heat quietly and evenly most of the time with just some twitter from a few rads as a drop of water tends to collect in the orifice (I do have one 'panting' rad which I will address in a separate thread).



The weather has been very unpredictable here on LI the last few weeks since Sandy (no damage knock on wood) and 69 does not always feel like 69 so I turn the tstat up to 70 or 71 to please the missus but then the rads go haywire and start hizzing and some sound like tea pots. The ptrol is bottomed out at .5+1 but the low pressure gauge tells me that when the boiler needs to do a long rung to increase the temp by 1-2 degrees it does not shut off on pressure until about 2psi. Clearly the ptrol is not accurate



Would a vaporstat solve this problem or would I just be creating a different problem with short cycling if i set the pressure to less than 1, which seems to be all my system can handle without freaking out.

nicholas bonham-carter

Poorly vented?

Only your good low pressure gauge can tell you if the air is escaping with no resistance from the mains. The shorter main might benefit from a switch from G-1to G-2, but you may see how it behaves from the back-pressure as it is venting.

If there were any change I would recommend, it would be to have all Hoffman 40's on your radiators, so that you have a constant back-pressure of radiator venting.

Later on, you may find some radiators, because of long run-outs, or risers, need a little more venting. It is just better to start with the H-40's. I know that this may be hard for many people on limited budgets to think of changing out their vents, but it is the correct way to start with balancing the air release, and subsequent steam arrival of any size one-pipe system.--NBC

malex

Rad vents and constant back pressure

It is very possible that I can improve the main venting even more but generally and in this specific situation the mains are satisfied before the risers get hot and my Vika 3psi gauge is not showing any pressure until the rads are hot, at least partially and the boiler keeps running to push up the temp the one degree.



Another thing is that the FocusPro tends to overshoot. If I go from 68 to 70 I end up with 72 until the rads cool and maintain 70 with no problem.



You recommend replacing my balanced Gortons with H40's to "have a constant back-pressure of radiator venting". Is you're recommendation based on some difference in how they perform? I know there is a difference as to how Gs and Hs operate with bimetal vs alcohol float. But it seems they would close at the same time if balanced correctly but I believe they open more quickly. Does this have something to do with it or is the point that I would be able to achieve more constant back pressure if I can get the system perfectly balanced, which would be easiest with H40s variable settings?



I believe the Gortons are pretty well balanced and I have a few extra so that I could play with the size on different rads. But it is possible that it could be more minutely balanced with H40s. I actually have a bunch that were on some of the rads before I switched to Gs. They probably just need a good cleaning.