vitogas 100 water temp

jim_51

Thanks Steve On most days yes. On the real cold days it seems to run all the time. Should I increase the curve on those days. I think when the unit was installed they set a limit of 160. Does that sound right?

jim_51

vitogas 100 water temp

I have a vitogas 100 with vitotronic 200 control. Copper fin baseboard throughout home. On the coldest days the water temp never gets above 150 -158. Is there a temp limit or should it put out at higer temps. Heat curve is set at 1.6 Is that normal. Thanks much.

S Ebels

Sounds normal

That's about right for a 1.6 curve. The main question should be; Is it heating your house at that water temperature? If so, you're saving energy $$ by not having the boiler run hotter than it needs to.

Is it keeping your house warm at that temp?

jim_51

vitogas 100 water temp

> That's about right for a 1.6 curve. The main

> question should be; Is it heating your house at

> that water temperature? If so, you're saving

> energy $$ by not having the boiler run hotter

> than it needs to.

>

> Is it keeping your house

> warm at that temp?



on very cold days it could be warmer

jp_2

cold days

so, on real cold days the house doesn't stay warm? i doubt you've hit a design day yet?

Bob R

Looking at the 1.6 curve in the operating manual it shows you should hit 158 deg. at approx. 20 deg outdoor. I don't know where you're located but fin tube generally requires higher temps than 160 at design. Final design temp really is dependent on the amount of radiation in the dwelling.
I'd say raise the slope to a 1.8 and be sure the adjustable high limit is set at 180.
Bob

S Ebels

Jim

You said in the post above that "it runs all the time" on cold days. Does "it" refer to the burner on the boiler or are you talking about the circulator and zones?

If "it" is the burner, that would indicate you have a mismatch in your heating load, system capacity and the output of the boiler.

I have rarely, very rarely, seen a boiler running flat out and never reaching the set point. Up to a point, good long run times are what a properly sized system is supposed to do. However, the Vitogas 100 is not a variable firing rate, it's either on or off, and our weather here at least has been now where near design, so that makes me wonder what exactly is going on.

jim_51

Thanks let me clarify on most days it will heat just great. We live in WI. On the really cold days it does not heat enough. The water temp never gets above 155 to 159.

Could the issue be that when installed the vitotronic 200 control they changed the factory preset fixed high limit from 230 to 212 on the vitotronic 200. In the manual it states that the adjustable high limit is factory preset to 165. Do not set the AHL above 165 if the fixed high limit has been set to 212.

The manual also stated that once adjusted the fixed high limit cannot be reset to 230. Should I try and reset the fixed high limit and the adjustable high limit?

Nick Ciasullo

Vitotronic 200

Jim,

Check to see where your Adjustable High Limit is set. It is usually set from the factory at 75C (167F). If it was not changed at the time of installation, it won't matter what you reset the slope to, your boiler will top out at 167F. Pull the know abk break out the tooth so it can go to 87C (178F). In the dead of winter, if your house is losing temperature, then you can adjust the slope up. I would try just one point at a time. Take it from 1.6 to 1.7 and wait half a day. If the house isn't catching up, bump it again. I would be very suprised if you need to go above 1.8 on the curve.