Four Way Mixing Valve

RoosterBoy

get yourself a taco I series zone valve ,spin in a by pass, a I series S will give you set point modulation on the return ,an I series R will give you out door reset on the field side.. these are really simple tools. my scanners down or i'd send some pictures.

there is nothing extra fancy with these zone valves ,they are really easy to wire and havent caused me any grief. Taco also makes a 3 way modulatiing I series S and R ,...i have yet to see any of the 4 way ,...although i have certainly been hanging in there with the Idea ,from thier product listing for a couple years , to now... I would really like to thank you for having the opportunity to help as i reached through the ethers and came up with a beautiful header designe while thinking about the Taco 4 way I series ....

Adam_11

Which would be the most ost effective application of a Four way mixing valve?.I am looking for something that will protect the boiler on start up and one that will monitor return tempuratures and throttle it accordingly with out getting into alot of controls.

hydronicsmike

I too....

...want to drive a BMW and pay for a Chevi-Sprint.

You'll need some sort of controller to get it done. Plenty of options exist. I have to send you the tekmar way. Thats who I work for. 250-545-7749. Call for options.

What you are looking to do, should be able to cost you a few hundret dollars. Think of it this way....if the boiler you have only lasts 3-4 years because it is being abused and not protected from thermal shock (cold return water temp hitting hot boiler) or continuous condensation on a non-condensing boiler, then what was a couple of hundret dollars on a properly controlled mixing valve? Your boiler should last you 20some years +, if protected and operated as suggested by the boiler manufacturer.

Someone here may suggest just to install a by-pass between boiler supply and return. The answer to that is that it is better than doing nothing and yes, it is probably cheaper...but it can not respond to any huge load changes in a system and not guarantee boiler protection as any motorized mixing device could.

I hope this helps.

Mike

Constantin

Tekmar offers 4-way valves as a retrofit,

though as Mike points out, they are pricier than the other way to protect boilers with flue gas condensation issues, namely an injection pump or pump logic.

For example, IIRC, the Buderus G115 uses pump logic while the boiler is attached to a primary-secondary heating circuit to maintain minimum boiler temps. Once the boiler comes to the lower limit, the boiler circulator shuts off and the boiler is allowed to recover before the circulator comes back on.

You can also retrofit injection mixing or 4-way valves to do the same thing to allow "dumb" boilers to reap the benefits of outdoor reset and the like. There are many solutions on the market, such as the Tekmar suite of 4-ways and injection-mixing solutions, the RMB mixing blocks from Taco, etc. Said prepared solutions are not cheap, but they do save a lot of installation time. After all, if you read and understand Siggy's Modern Hydronic Heating tome, you can build your own injection system.

I'd take Mike up on his offer. Call him up and discuss your options. He's a great guy!