Ball valve location on Danfoss Thermic valve

[Triumph562]

After plumbing my new EKO 25 and thermal storage, I realized I forgot to add a ball valve on the bypass between the boiler output bypass to the Danfoss VTC511 valve. I realized this as my storage is slow to heat up, and was throwing the E-2 overheat code a couple times and shutting down. The water never had a chance to get out to storage quick enough. As an aside, the actual supply outlet temp was only 150, and the return temp 140. I'm thinking I might have other problems with the temp sensor or controller.

I do have a bypass loop around the 3 way valve on the return side. This was recommended by Tarm Biomass so did do that. I noticed if I crack this valve open 1/16th a turn or so it lets a little more water through to the return. I haven't done a long burn with this yet but I feel this would solve the issue, or have the same end result as a valve on the outlet side.

Do I still need a ball valve on the outlet supply bypass line, if I can utilize the bypass on the return as is?

 

[Smoothride]

A diagram of your set up would help.

 

[Triumph562]

Here is how it is set up.

 

[chew72]

Where is your circulator in all this? And how much storage do you have? You do want to keep the bypass closed. And to me it sounds like it might just be coming up from a very cold start. When I first filled my boiler the water temp was around 50f so I was mixing a lot of my output flow to bring it up to 140f.

I also had to add an air vent in the line from the supply to the mixing valve. It trapped air and with no water to mix, the thermostatic mixing valve would not allow hardly any flow.
My issue came from having to have 5 ft horizontal pipe in order to put the mixing valve where it can be accessed.

 

[Triumph562]

Where is your circulator in all this? And how much storage do you have? You do want to keep the bypass closed. And to me it sounds like it might just be coming up from a very cold start. When I first filled my boiler the water temp was around 50f so I was mixing a lot of my output flow to bring it up to 140f.

I also had to add an air vent in the line from the supply to the mixing valve. It trapped air and with no water to mix, the thermostatic mixing valve would not allow hardly any flow.
My issue came from having to have 5 ft horizontal pipe in order to put the mixing valve where it can be accessed.

Here is a more detailed drawing of the whole system. It's based on a Tarm Biomass concept drawing from 2010. The major flaw is the return water is being mixed with the supply water before it reaches it's useful destination. A possible fatal error on my part. Haven't really tested it yet.