busy mixing valve

rod robbins

Hello guys
I have only instaled my system and dont have the experiance to confirm things are working as they should.The system seems to work well.
My question is i have a motorised mixing valve for the floor slab with a wirsbo outdoor reset controler.When i watch the valve in operation it opens in small amounts and the temp responds acordingly.As it reaches its design temp it sometimes oveshoots a degre and rather just close the valve a bit it closes the valve all the way and the supply temp falls to the bottom.Then it starts the process over.Could i have something set wrong in my controler?Do the mixing valves work this way normaly?
Also thanks for all the help in here.I dont post much.I can usualy find my answers with the search button.I could not have had the fun of building this system without the help.

Constantin

Odd...

... the valve shouldn't modulate like that. Granted, I have a different brand, but mine pretty much stays in the same position all the time.

The valve should be calculating heat losses ahead with the OR controller and indoor temp feedback. There should be no overshooting, just a simple PID curve up to temp and minor modulation up-down from there as the valve flutters to match the heat gain to the room via the floor to the heat loss.

Who is the manufacturer of this valve and have you tried to contact the manufacturer for tech support?

hydronicsmike

Hunting?

If it appears to be hunting back and forth, in most cases this is an indication of having the valve oversized. In other words, too big.

Mike

Tim Doran

Agree

I agree with Mike. It's sounds like the Cv is too high for the application. How was it sized? Call us if you want to go over things. Ask for tech. 800-321-4739

Tim D.

rodr

Thanks for the responce.The valve is a wirsbo A3131000 1"inch (cv10) with wirsbo system pro 311 controller.The system was designed with wirsbo software and the help of the local distributer.I have a call into Tim who i am sure will answer all my questions.
Rod

Aidan (UK)

mixing valve

".....it sometimes overshoots a degree and rather just close the valve a bit it closes the valve all the way....."

I'm not familiar with the controller. Is there a flow temperature high-limit thermostat or sensor and, if so, what is it set at? Would it cause the valve to close if it's set temperature was exceeded?

rodr

update

I talked to Tim at wirsbo and found that i had the controler set at motor speed of 145 and the correct speed for the mixing valve was 95 seconds.After the change the valve seems to be moving a lot less and holding the temp very steady.I sure like the support at wirsbo.
Rod

hydronicsmike

Tim Doran...

...is one of the finest people in the industry and the folks at Wirsbo altogether are a Top-notch team. Only second to the guys at tekmar

Tim Doran

Thanks!!

Thanks for the kind words Mike. It means a lot comming form someone that I hold in a very high regard such as yourself. Tekmar certainly has a fine team, we may have to arm wrestle or something over that pecking order thing though.

Tim D.

hydronicsmike

Was wondering what took you so long....

...to bring up my pecking order

let's just both agree on a 4-way TIE with two others that we wont mention. That way nobody know who the other two are and nobody can get hurt or broken heart feelings.:)


And thank you very much for your kind words. It definitely goes both ways.

Enjoy your long weekend.

Mike