Viessmann Vitodens 200-W B2HA heating issue

[gmartine]

Have you calibrated and offset the Tado TRV temps?

Might not make much difference but they are obviously reacting to the nearby radiator air temperature and not necessarily the actual room temp.

 

[kgfx_5]

Have you calibrated and offset the Tado TRV temps?

Might not make much difference but they are obviously reacting to the nearby radiator air temperature and not necessarily the actual room temp.

Yes, long time ago. There is no big difference surprisingly, less than 0.5 C

 

[John.g]

Right now, for example, I see the picture of boiler that turned off burner and for whatever reason temperature doesn’t drop fast, so this time it managed to heat something. But, difference between flow and return on LLH is 2 C. While there are still 5 radiators open, not including UHF and other stuff.

The temperatures should drop rapidly if both pumps are still running which they should be, we don't know what the primary pump is circulating but would think its quite high.
You can derive what the secondary Wilo pump is pumping from the following info.

Get the pump model and pump head
See where the setting knob is pointing to, it will be either to C1,C2, C3, or to the right of C3 or to the left of C1, but don't touch it.
Watch the Wilo while its starting up and you will see the set head flashing for a few seconds and then reverting to showing the power in watts W,make a note of this and the watts W and post same and the flowrate can then be read off the pump curves, might reveal something and will certainly be handy for showing the flowrates with different heating combinations.

 

[John.g]

Is the secondary pump installed correctly, the boiler circ pump is pumping into the top right primary pipe and returning through the bottom right primary pipe via the secondary pump, thought the secondary might be pumping into the bottom left secondary but maybe not?.

 

[John.g]

Is the secondary pump installed correctly, the boiler circ pump is pumping into the top right primary pipe and returning through the bottom right primary pipe via the secondary pump, thought the secondary might be pumping into the bottom left secondary but maybe not?.

Or pumping from the top (left) secondary pipe since the boiler pump will more than likely be pumping through its own heat exchanger.

 

[kgfx_5]

You can derive what the secondary Wilo pump is pumping from the following info.

External heating circuit pump is always set to 40 W power, never seen it to change. Boiler can and does turn it off when there is a need for DHW, but in any other time it is turned on.

Is the secondary pump installed correctly

The Wilo pump on this picture is not a heating circuit pump as far as I get it. If i remember correctly, this pump helps the return flow back into the boiler. The main heating pump can be seen on the last picture. I would guess that all pumps do work as intended, because sometimes boiler works and heats the house correctly?

 

[John.g]

Does this mean that all the flow of water through the boiler is via this pump, it showed 15W in one picture, if so then we can derive the boiler flow if you provide the info, above.

 

[kgfx_5]

Does this mean that all the flow of water through the boiler is via this pump, it showed 15W in one picture, if so then we can derive the boiler flow if you provide the info, above.

I think there is this pump + own boiler's internal pump?

 

[John.g]

The reason I'm labouring the point a bit is that I feel the boiler should run for more than 11 secs if the flowrate through it is - 35LPM and I can derive that as long as the discharge from that Wilo pump goes straight into the boiler return, I can't see quite clearly if there is another T above it before the boiler, so just look up that info and we can see exactly what it's pumping.

 

[ShaunCorbs]

Should be a sticker on the top at the back left can you take a pic of that plz as I’m sure there isn’t a pump inside the boiler just a heat only

 

[John.g]

Have a look at the attachment to see if pipe and the other Wilo is teed into the boiler return.

 

[gmartine]

@SC. I looked it up at the time and it came up as a system boiler.

7571049

7571049 Vitodens 200-W B2HA 49kW System Boiler

viessmanndirect.co.uk

 

[ShaunCorbs]

Is that with an external pump set as I don’t know if one (42kw) with an internal set ?

 

[kgfx_5]

Should be a sticker on the top at the back left can you take a pic of that plz as I’m sure there isn’t a pump inside the boiler just a heat only

Attached.

Have a look at the attachment to see if pipe and the other Wilo is teed into the boiler return.

Attaching photo. This pump is set on c2, 15 W.

——
I appreciate Your help, guys. Thank you.

 

[kgfx_5]

Is that with an external pump set as I don’t know if one (42kw) with an internal set ?

I am guessing that my boiler has internal pump based on the information shown in ViCare app. I could be wrong.

 

[ShaunCorbs]

could be the external as its wired to the boiler

 

[John.g]

Attached.

Attaching photo. This pump is set on c2, 15 W.

——
I appreciate Your help, guys. Thank you.

Thanks,
The other Wilo is feeding into the boiler return as well so looks like the main (a external) pump.
Can you post a photo of this one as well please with the same info re type, head etc and its setting and power.

 

[kgfx_5]

Thanks,
The other Wilo is feeding into the boiler return as well so looks like the main (a external) pump.
Can you post a photo of this one as well please with the same info re type, head etc and its setting and power.

You mean a pump that is in lower left corner of the picture? This is a DHW pump. It turns on when there is a need to fill and heat hot water cylinder.

 

[John.g]

When DHWP off then all the water into the boiler flows via the 4M Wilo pump, I can't find a curve for the C2 setting but it looks very much as if the flowrate isn't much more than 1 m3/hr, next time its running can you turn the setting knob to the right until its flashing say 2M then stop and read off the power, W, adjust it then until the power is the same as it was on C2, note the head and return it to C2, I have the pump curves for the CP (constant pressure) settings.

 

[John.g]

Should have added also turn the setting knob briefly fully clockwise and read off the power before returning it to C2.