My usual server is off line, so I cannot find the original thread..

Today the VRC 470F was delivered, so I got stuck in a removed all of
the old controls and fitted the VR 65 and VRC 470F - this after getting
house and water to a good temperature, in case it took longer than
expected.

I had it all ripped out and new back in, within 3 hours. CH was
obviously working fine, but not so sure about the HW side. CH now runs
much more gently, modulates output down to minimum instead of the near
flat out or off as before, boiler never seems to exceed 50C, so well
inside condensing range.

I had VRC 470F running on its batteries for several hours, without the
boiler etc. powered and it retained it time and date just fine. Maybe
because the clock is in the 470F and is maintained by the batteries,
your 470 has no battery rather it is powered from the ebus. Power the
boiler down, no ebus power, clock is lost, but the settings are in non-
volatile memory?

The HW issue...

I configured the boiler to assume a mid position valve, but it seemed
not to make any difference other than the boiler then allowed me to set
a max temp for the HW, but only a max of 50C. Before changing the
control system, I was able to set a max boiler output temp of 75C.

470F Menu Installer Level System Config. seems to suggest a Flow
Temperature Target 40C, though I have seen this show 51C. It does not
allow it to be changed..

There was a 'desired HW temp' setting in the 470F which could be set to
a max of 70C.

I initially had the HW running on its cylinder stat. and it never
seemed to try to heat the HW, maybe because it was already well over
50C, but I never saw the valve move at all.

I then swapped from stat., to the NTC sensor. I was than able to see
the HW cylinder temperature on the 470F, it seemed to be just
maintaining a constant 50C, but not much HW was consumed today so I
cannot be sure, but I never saw the valve move to HW or the mid
position. Except by pulling the NTC out of the cylinder insulation and
allowing it to cool, did cause the valve actuator to move.

HW Boost didn't seem to do anything.

I wonder if the legionella setting, once per day might overrule the
boiler, if it is the boiler holding the temperature down.

I set the clock deliberately 5 minutes fast, to see if the DCF77
receiver corrected it, as there doesn't seem to be any indication of
reception. It hasn't corrected it yet, maybe over night reception? That
is probably in the remote outdoor sensor and the 470F is showing the
correct outdoor temperature.

For anyone interested - Boiler is a Vaillant 418 ECOfit Pure, valve
actuator is a Sunvic SDM 1901.

Vaillant have been downright unhelpful (three times), when asked if the
VCR 470F + VR65 + my boiler would work properly together. It seems they
do, if I can solve the HW issue.

On 18/01/2019 22:41, Harry Bloomfield wrote:

My usual server is off line, so I cannot find the original thread..

I have been a bit "off line" myself - flu, and possibly the real thing
rather than the "man" variant!

Today the VRC 470F was delivered, so I got stuck in a removed all of the
old controls and fitted the VR 65 and VRC 470F - this after getting
house and water to a good temperature, in case it took longer than
expected.

I had it all ripped out and new back in, within 3 hours. CH was
obviously working fine, but not so sure about the HW side. CH now runs
much more gently, modulates output down to minimum instead of the near
flat out or off as before, boiler never seems to exceed 50C, so well
inside condensing range.

Yup that sounds like its doing what it should.

I had VRC 470F running on its batteries for several hours, without the
boiler etc. powered and it retained it time and date just fine. Maybe
because the clock is in the 470F and is maintained by the batteries,
your 470 has no battery rather it is powered from the ebus. Power the
boiler down, no ebus power, clock is lost, but the settings are in non-
volatile memory?

Yup, no batteries on mine...

The HW issue...

I configured the boiler to assume a mid position valve, but it seemed
not to make any difference other than the boiler then allowed me to set
a max temp for the HW, but only a max of 50C. Before changing the
control system, I was able to set a max boiler output temp of 75C.

470F Menu Installer Level System Config. seems to suggest a Flow
Temperature Target 40C, though I have seen this show 51C. It does not
allow it to be changed..

The flow temp should just reflect what the "system" is calculating is
the ideal for the circumstances (external temp etc). So you don't set it
directly. If you play with the Heating curve then you can influence the
slope of the mapping between target flow temp based on outside temp.

IIRC the thing comes preset to a curve of 1.2. That would mean with a
external temp of ~5 deg you would see a max CH flow temp of around 50
(if you have the internal temp set to 20 - it will alter the flow temp
in response to the actual temp demanded as well).

Depending on how good the house is thermally you may need to tweak that.

There was a 'desired HW temp' setting in the 470F which could be set to
a max of 70C.

I initially had the HW running on its cylinder stat. and it never seemed
to try to heat the HW, maybe because it was already well over 50C, but I
never saw the valve move at all.

I then swapped from stat., to the NTC sensor. I was than able to see the
HW cylinder temperature on the 470F, it seemed to be just maintaining a
constant 50C, but not much HW was consumed today so I cannot be sure,
but I never saw the valve move to HW or the mid position. Except by
pulling the NTC out of the cylinder insulation and allowing it to cool,
did cause the valve actuator to move.

HW Boost didn't seem to do anything.

That basically gives priority to HW generation even if you have the DHW
programmed off at that time. However it will only fire the boiler if it
sees the cylinder below set point, then once its reached set point it
will revert to its normal programming.

I wonder if the legionella setting, once per day might overrule the
boiler, if it is the boiler holding the temperature down.

I have mine set to 60 for "normal" and 70 for the once weekly cycle.

I set the clock deliberately 5 minutes fast, to see if the DCF77
receiver corrected it, as there doesn't seem to be any indication of
reception. It hasn't corrected it yet, maybe over night reception? That
is probably in the remote outdoor sensor and the 470F is showing the
correct outdoor temperature.

For anyone interested - Boiler is a Vaillant 418 ECOfit Pure, valve
actuator is a Sunvic SDM 1901.

Vaillant have been downright unhelpful (three times), when asked if the
VCR 470F + VR65 + my boiler would work properly together. It seems they
do, if I can solve the HW issue.

The CH temp ought not affect the DHW flow temp - for weather
compensation to be practical its got to be able to run different flow
temps for DHW since it would otherwise only be during fairly server
weather you would be able to adequately heat the water.

--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

My first thought on seeing the subject was Crikey! Someone has bought an
old car and found John's details in the log book :-)

--
Graeme

Harry Bloomfield submitted this idea :
I configured the boiler to assume a mid position valve, but it seemed not to
make any difference other than the boiler then allowed me to set a max temp
for the HW, but only a max of 50C. Before changing the control system, I was
able to set a max boiler output temp of 75C.

Correction...

The actual boiler setting (on the boilers LCD) were 75C for CH and 50C
for HW. Both set on their max.

This morning the cylinder temperature was showing 44C, so I tried the
Boost setting. That seemed to raise that temperature to 47C.

The 5minutes fast on the time, didn't correct itself, so maybe it lacks
the DCF77 receiver.

Get well soon!

Harry Bloomfield brought next idea :
I had VRC 470F running on its batteries for several hours, without the boiler
etc. powered and it retained it time and date just fine. Maybe because the
clock is in the 470F and is maintained by the batteries, your 470 has no
battery rather it is powered from the ebus.

I have still not solved the HW issue, but (too) early this morning the
CH came on and brought the house up to temperature. I then found the
470's clock was showing 22:30 05/05/19 when the CH ought to have been
on. My best guess is that it is actually fitted with a DCF77 receiver
and maybe received corrupted data from DCF77 changing the time and date
to the wrong data. Nothing else was corrupted, you would have thought
they would have done a check sum on the received data?

In article ,
says...

Harry Bloomfield brought next idea :

Nothing else was corrupted, you would have thought
they would have done a check sum on the received data?

There is no check sum but there are three parity bits, one on
the minutes, one on the hours and one on the day/date data.

https://en.wikipedia.org/wiki/DCF77#...interpretation

--

Terry

---
This email has been checked for viruses by AVG.
https://www.avg.com

On 19/01/2019 07:52, Graeme wrote:

My first thought on seeing the subject was Crikey! Someone has bought an
old car and found John's details in the log book :-)

Thinking about that, with that plate is would have been registered the
year I was born ;-)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

After serious thinking Terry Casey wrote :
There is no check sum but there are three parity bits, one on
the minutes, one on the hours and one on the day/date data.

https://en.wikipedia.org/wiki/DCF77#...interpretation

Well I knew that, I just class it all as a 'check-sum'.

The clock's data became corrupted a second time too, Sat/Sun.

I carried out some more tests yesterday, on the HW heating, setting it
run a legionella cycle. That caused the boiler to run 85C, which raised
the HW a few degrees above the 50C, but the SDM 1901 actuator then
began cycling. Radiator/house temperatures increased due to this valve
cycling. So my best theory now is that the VR 65 is not compatible with
a Sunvic SDM1901 actuator, but Vaillant offer no clues as to what
actuators it should work with - they just state a 3-port mid position.

In message , John
Rumm writes
On 19/01/2019 07:52, Graeme wrote:
My first thought on seeing the subject was Crikey! Someone has
bought an old car and found John's details in the log book :-)

Thinking about that, with that plate is would have been registered the
year I was born ;-)

Thanks John. Now I feel *really* old :-)

--
Graeme

Harry Bloomfield wrote :
I carried out some more tests yesterday, on the HW heating, setting it run a
legionella cycle. That caused the boiler to run 85C, which raised the HW a
few degrees above the 50C, but the SDM 1901 actuator then began cycling.
Radiator/house temperatures increased due to this valve cycling. So my best
theory now is that the VR 65 is not compatible with a Sunvic SDM1901
actuator, but Vaillant offer no clues as to what actuators it should work
with - they just state a 3-port mid position.

I managed to get through to Vaillant Trade Tech. They assured me that
the VR65 is compatible with ALL makes of 3-port mid position valve
actuators. I thought there were some differences?

The also said to ignore the flow setting for HW on the boiler, it only
applies when it is a combi type, but it is common software.

I tried my spare Sunvic 1901 and got the same result. Fine on CH, on HW
it seems to dither about and chuck heat at the CH circuit.

Sunvic SDM 1901 works as below..

Blue = Neutral
Make orange live = HW Only
Make White + Grey live = CH Only
Make White + Orange live = mid position HW + CH
There are two mid positions.

Orange live signals boiler/pump to run. Actuator is a momo, only
rotating in a single direction under motor power until it achieves
position.

Is this the same as Honeywell's 3-ports?

replying to Harry Bloomfield, Bal wrote:
Hi, what system diagram setting did you use. I have a vented system and
originally had it on 1 when I fitted a couple of months ago it started playing
up today giving me a heat generator not found error. Only noticed when the
house became really warm and despite the thermostat being at the target temp
the heat continued. Had to do a power down. Many thanks

--
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