anyone got any more ideas. Think mickyg fits plenty of these. You can disregard the mprt as even on not proportional control does it wait 5mins before ramping
Gloworm ultracom 2 sxi problem with Myson mprt smart stat
- Thread starter scoobydo123
- Start date
still struggling with this one. Really need to know if this is normal behaviour any got one?
bump for hopefully mickyg or other regular to help please.
Picasso sorry didnt get an alert that you have replied. By ramped down do you mean during the 2nd burn?
To confirm the scenario is from cold the tpi stat calls for heat with no proportional control, as it nears the set point of the stat proportional control then cuts in. However the boiler has some rather silly logic where it waits for x minutes before ramping up to the value of d.0 without considering the lack of any meaniful rise in flow temps.
To quote tech support:
After ignition, the burner goes into a reduced power for 1 to 5 minutes:
*1 minute if the heating requirements are high
*5 minutes if the heating requirements are low
A high heat requirement would let the software check the target temperature and the current flow temperature.
For example =
Set point 80 degrees C
Current Flow temp 40 degrees C
This then would allow the boiler to use the 1 minute short cycle.
End quote
This is an extremely poor logic with low granularity as the boiler sits on low gas with very little heat gain for 5 minutes even though the system can take much more heat input. After the 5 minutes it will then ramp up but this clashes with the TPi logic. I will go round to test this theroy by raising the flow temp target currently set to 67c but this goes against the whole idea of reducing flow temps for energy efficiency.
To confirm the scenario is from cold the tpi stat calls for heat with no proportional control, as it nears the set point of the stat proportional control then cuts in. However the boiler has some rather silly logic where it waits for x minutes before ramping up to the value of d.0 without considering the lack of any meaniful rise in flow temps.
To quote tech support:
After ignition, the burner goes into a reduced power for 1 to 5 minutes:
*1 minute if the heating requirements are high
*5 minutes if the heating requirements are low
A high heat requirement would let the software check the target temperature and the current flow temperature.
For example =
Set point 80 degrees C
Current Flow temp 40 degrees C
This then would allow the boiler to use the 1 minute short cycle.
End quote
This is an extremely poor logic with low granularity as the boiler sits on low gas with very little heat gain for 5 minutes even though the system can take much more heat input. After the 5 minutes it will then ramp up but this clashes with the TPi logic. I will go round to test this theroy by raising the flow temp target currently set to 67c but this goes against the whole idea of reducing flow temps for energy efficiency.
CH demand from grasslin programmer to stat this to the Honeywell mv switched orange to the boiler. So with this config the stat switches off and the mv closes this is not helping obviously. Was thinking of putting a timer relay to hold the mv open for 5mins
cheers
cheers
going round there in a minute, it is not so much that the boiler is short cycling it is that it will not go on high gas rate for 5mins which clashes with the logic on the mprt but will report back
Boiler showing S4 whilst on low gas sits for 5 mins only then does it ramp up. Whilst it is waiting to ramp d.40 is actually reducing. There is no issue with flow as I can put it all full whack and differential is fine. Also set pump to always on at maximum rather than only when burner lit. Put flow up to 80 when the boiler came on d.40 was 50c and still it waited 5 mins.
Yep done the OIL thing before but really wanted to try and resolve it.
I want to know if I have fault or it is just how these work? Tech support had a word with the technical trainer after I pushed for details of the algorithm that decides when the boiler should ramp up and they gave me the details I posted surely if d.40 is not increasing then the boiler should increase output in a timely manner.
Going to try it with a normal flow rate of say 67 let the stat go into TPi mode but park the MV open whilst it waits for the next call for heat and have pump overun set to 10 mins. This should in effect push the flow temp down much further before the boiler kicks in hopefully this will be positive what do you reckon? Had the idea whilst on the way to work and it has me thinking why dont we plumb like this in the first place rather than dumping down the bypass? Obviously keeping the bypass just in case? Have patented the idea in work is it a good one anything negative about it?
Thanks for sticking with me have you seen this boiler in action? I think there is another bit of logic going on potentially?
I want to know if I have fault or it is just how these work? Tech support had a word with the technical trainer after I pushed for details of the algorithm that decides when the boiler should ramp up and they gave me the details I posted surely if d.40 is not increasing then the boiler should increase output in a timely manner.
Going to try it with a normal flow rate of say 67 let the stat go into TPi mode but park the MV open whilst it waits for the next call for heat and have pump overun set to 10 mins. This should in effect push the flow temp down much further before the boiler kicks in hopefully this will be positive what do you reckon? Had the idea whilst on the way to work and it has me thinking why dont we plumb like this in the first place rather than dumping down the bypass? Obviously keeping the bypass just in case? Have patented the idea in work is it a good one anything negative about it?
Thanks for sticking with me have you seen this boiler in action? I think there is another bit of logic going on potentially?
d.0 was on 22 only put it up to 30 just to prove a point that flow is good 
Does seem strange but without knowing exactly what parameters the logic works it is hard to understand if it is a fault or it just doesn't like my system configuration. Had trouble with Vaillant for years on the 4xx series but that has been resolved with the new firmware that was developed in France. Anything in the combustion chamber about this
Does seem strange but without knowing exactly what parameters the logic works it is hard to understand if it is a fault or it just doesn't like my system configuration. Had trouble with Vaillant for years on the 4xx series but that has been resolved with the new firmware that was developed in France. Anything in the combustion chamber about this
looks like your running out of options 
, must admit I never realised that the boiler sat for 5 minutes on low fire when the boiler is hot, as a last resort I would close the internal bypass to give full pressure and flow to the system, still get a niggle that its a flow issue.
, must admit I never realised that the boiler sat for 5 minutes on low fire when the boiler is hot, as a last resort I would close the internal bypass to give full pressure and flow to the system, still get a niggle that its a flow issue.
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