Varivalve issues!

miana

I am having problems with explosive steam exiting my radiators.  At the end of last season I replaced all the valves on my radiators (10) with the varivalve - as recommended by my plumber.  This is the first full season they are being used - as I waited to replace them when the heat was off.



The problems I am having are all in the back of my house (if that matters).  The problem only occurs if the heat has gone off (meaning the water runs out) or - if we are raising it significantly.  I usually keep it at a steady 66 or so.  First I get a really loud noise - not a banging - and then huge amounts of steam come blasting out of the valve.  I have tried 'closing' them - or moving the lever closer to closed rather than open.  Last night the heat went off - as the water had run out.  We woke up to a 53 degree house.  We refilled the boiler and turned the heat up to 66.  Two radiators at the back of the house went crazy.  The one upstairs - just dripped water out of the valve opening until there was a small pool - the one on the first floor - directly below - spewed steam!  I lowered the heat - threw a rag on the valve.  This is the 3rd time this has happened.  I was under the impression that these valves were the answer to all my banging and escaping steam problems.  I no longer have the hammering the 'steam train' is significant.  Can anyone help? Please!

BobC

Varivalves

can be useful for specific problems but they are not a panacea and should not be used on many systems. Most systems work best with fast main venting and slow radiator venting. That way the steam can arrive at all the radiators simultaneously and heat everything at about the same time.



Varivalves can be handy to solve specific problems but they are known for having problems when there is a lot of water present in a steam system. The faster you vent, the more condensate you are likely to make and if you have any pitch problems in the piping it's a perfect recipe for fountaining vents.



All horizontal piping in the system should be checked with a level to be sure the piping is pitched so any water can find it's way back to the boiler. radiators should be checked with a level to be sure they are pitched so water can drain out towards the steam supply pipe. Next find out what pressure the boiler is running at when making steam it should be 2 PSI or less. Has the pigtail at the base of the pressuretrol been checked to be sure it's clear? If that plugs up the boiler might be running at higher pressure than it should and that makes all problems worse.



Also is the boiler piping correct and does it agree with the manufacture's piping diagram in the install manual?



Bob

nicholas bonham-carter

High pressure problems

Don't forget that the radiator steam inlet valves must never be turned off. Water will collect in the radiators when they are partially closed, and starve the boiler of water. Running the boiler out of water puts stress on the expensive parts and contributes to the plumbers early retirement fund.

If the boiler has been piped according to the manufacturers strict instructions, then cleaned (skimmed), and adjusted to run at no more than 2 psi maximum, then things should be better. Look to see if you have new main vents on the returns.--NBC

BobC

Why

is the boiler running out of water? unless the radiators are squirting quarts of water on the floor you have a leak that has to be found and fixed. Adding significant amounts of water will kill a boiler and that makes the cost of fixing a leak pale in comparison.



Bob