Gloworm ultracom 2 sxi problem with Myson mprt smart stat

[scoobydo123]

Guys,

Got a Gloworm ultracom 2 that exhibits strange behaviour in the start up routine. The boiler sits on low gas for at least 5 minutes before rising to what d.0 is set. This is causing issues with the room stat as it calls for heat towards the end of when the stat is going to be satisfied. As the boiler takes so long to put any decent heat into the water I find I only get a short burst at the correct rate before the stat clicks off even though room temp has not been met. Obviously this is good in one respect as returns are kept quite low but I feel the timer that is apparent on the boiler is reducing efficiency and causing delays in heat up of both CH and DHW recovery (go a fast coil). Do they all do this and is there a setting that can be adjusted for this timer.

Thanks

 

[scoobydo123]

Any Gloworm experts got any ideas? Is it normal for the ultracom 2's to behave like this (very long time before it rises to d.0)

 

[petertheplumber12]

I believe that is the anti cycle timer that is conflicting, If you have the boiler manual which you should have, go to page 28 section 13.2 and Page 29 code D.67 and that tells you how to control the anti cycling time, you may need to shorten it to 2 mins.

 

[Andygasman2010]

Check the status code during the problem.

 

[scoobydo123]

Peter the plumber it is not the anti cycle as the boiler is actually firing as expected with the proportional control but is sitting on low gas for a very long time before rising to d.0

Andygasman, will try to take a look of the s codes during the issue but think it will just be normal call for heat.

Just to ensure everyone understands the issue, even for HW only demand so no algorithms to worry about. The stat will calls for heat but there will be a substantial delay before the boiler will rise to the value of d.0 I think this is a timer someone in the boiler that tells it to wait for x seconds before looking at the value of d.0. Will try and get round there to see if it is consistent.

Thanks for the input

 

[petertheplumber12]

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[picasso]

 

[Andygasman2010]

OP.

It's designed to sit at low rate for up to 5 minutes depending on load so either water isn't getting away quick enough or it's an electronics issue. Might be worth ringing Glowworm before you fit anything.

(Thanks to Harold5 in the CC)

 

[scoobydo123]

When the system finally ramps up heat gets away fine. However interesting that someone in the CC has said could be a electronics issue. So from a totally cold system would you expect it to sit for a long time before ramping up as I can check this tomorrow on a cold system and time it. What logic would say if ΔT in y time ignore d.0 for z.

 

[Andygasman2010]

It looks at flow / return temps and the differential to decide, but I'm not sure what the parameters are and why it decides to do what it does.

What's your pipe sizing like? how big is the house?

 

[scoobydo123]

22mm for the first 1M after the boiler then 28mm for 6M reducing to 22mm for the S PLan then 28mm on main runs reducing to 22mm near rads. 4 Bed semi 4 ensuites plans to increase by 50% (double side extension 4M rear extension and loft conversion providing another 2 beds with ensuites) with 2 ground floor ensuites to be gravity fed DHW so another fast recovery cylinder. Once the system does respond to d.0 20c differential is maintained and in general happy with performance apart from this niggle.

Thanks

 

[Andygasman2010]

22mm for the first 1M after the boiler then 28mm for 6M reducing to 22mm for the S PLan then 28mm on main runs reducing to 22mm near rads. 4 Bed semi 4 ensuites plans to increase by 50% (double side extension 4M rear extension and loft conversion providing another 2 beds with ensuites) with 2 ground floor ensuites to be gravity fed DHW so another fast recovery cylinder. Once the system does respond to d.0 20c differential is maintained and in general happy with performance apart from this niggle.

Thanks

Why go from 22 to 28 to 22 to 28mm?

This could be normal operation, check with S codes just in case and give glowworm a ring.

You might want to try these when you upgrade...

http://www.glow-worm.co.uk/products/controls/climaprosub2-sub-rf/

http://www.glow-worm.co.uk/products/controls/smart-wiring-centre/

http://www.glow-worm.co.uk/products/controls/new-wireless-outdoor-sensor/

 

[Andygasman2010]

Actually, are you proposing two cylinders? I don't think you can use the Glowworm controls with two.

 

[scoobydo123]

28 to 22 to 28 was due to have a bundle of 28mm hep going spare so used it. Got the same from the megaflo as well feeding the ensuites and balanced cold water. Have always had my eye on the climapro 2 but not sure if the software allows a 1 off override with it going back to the planned program. House is a HMO (house of multiple occupancy) that I pay the energy bills. With the current MPRT which does a sterling job of maintaining the temperature and keeping the return below 55 during the heating period after the initial burst. This stat also has the advantage of a 1hr boost to the high preset temp this is very useful for when someone has a day of work they just press the button and I dont get hit with a large bill.

Yes the original plan was 2 cylinders not actually for the amount of stored water required but to have two diverse systems. 6 showers so designed around the gravity system for the gnd floor for max head and a large storage tank in the loft with flow restrictor so as to not starve the megaflo when simultaneous demand from the 2 diverse systems. However I have since purchased another property rather than go through the expense of the extension and used the money set aside as the deposit (made more financial sense). So can perhaps consider the WC if controls can be locked down with an override option for when someone is off work without the need to reset back to normal settings.

If this is normal behaviour (anyone got any real world experience of these) then I do wonder how the Ultrapower gets it claimed recovery times as it does not pan out to how long it waits before putting any real load into the system, unless it is running very different software?

 

[scoobydo123]

Right update time.

Was round the place yesterday waiting for the DNO to come out to replace faulty electric head.

Boiler from cold will fire on high gas rate from cold within 15 seconds or so. However subsequent fires sit on low gas for the same amount of time which happens to match the proportional time of the MPRT stat plus 3 seconds so only get a 5 second high gas burn! First burn got the room to within .5C of target temp and flow got to 68c return 48c target flow 72c. When the stat then called for heat again the flow had dropped to 55 and return 48 (due to bypass?). the boiler then sat for around 5 minutes on low gas with no real increase in flow temp 57c return less than 50 and only gave a 3 second high rate burn before the stat switched off.

Anyone got any ideas or do they all wait this long on subsequent burns?


Have even tried to put d.0 to 30kw with no change to behaviour from cold and delta was maintained so circulation is good.


Would changing the stat logic to OIL boiler increase length of allowed burn?

Have also changed pump behaviour to be max when burner lit