I have a shaver 290 and for the most part it is great, but like some of you I have had a couple issues. My biggest concern is the water steaming off, I am down several gallons a day and steam constantly at all temps. My friend, who has the same furnace uses no water in a 2-3 week time frame and has basically the same installation with the same parts. I think I have discovered the difference in our boilers and why some Shavers steam more than others. I've attached an image depicting our installations. My boiler (Boiler B) has a slight lean to the rear, where my friends (Boiler A) has a slight lean to the front, and possibly an upward angle of the vent tube exiting the boiler. I believe the lean frontward lean and upward angle of the vent pipe on my friends boiler dramatically cuts down on the surface area of water exposed to the atmosphere. Boiler A's vent pipe is full of water, where Boiler B's is simply a passage way for the atmosphere to make contact with the entire surface of the water in the tank allowing much more steam to be created and exit even when the water is below boiling. I slid a 1" piece of pex over my overflow and and secured it with a hose clamp. Then added a short 90* and another 1-2" of pex vertically. The boiler water level is now raised slightly, but would still be vented and the surface area of the water exposed to the atmosphere would only be the area inside the vent pipe instead of the entire top of the tank. Another side benefit is I can see my water level in the pex, as I have a pink rust inhibitor additive that shows through the pex. If you run straight water clear flexible pipe attached to the vent, bent upwards and held in place with clamps on the side of the boiler should be an easy fix, just don't extend the pipe up too far or you may risk overflowing out the water coil cover. Here is a quick sketch of the two scenarios (boiler A and boiler B) as well as a diagram of my proposed fix (bottom right). I've been running this for a day now and have seen zero steam and have lost zero water. I don't think the water in the pex will ever freeze as mine is quite hot (160*+). Does anyone see any problems with this? I sent an email to shaver for their input and am awaiting a response.