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Help required wiring my ASHP/UFH


joe90

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8 minutes ago, joe90 said:

I got my command unit from a carrier branch In England, Southampton I think. People on the forum were searching for them, I just rang Carrier in America and they gave me the number to ring over here, an on the shelf item.

Do you recall what sort of money it was? 

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Right, I think I have a plan!, still trying to source a new board for the ASHP, have messaged the French supplier that @Gav_P bought one from on Ebay to see if they can supply another one., if not it’s the Netherlands as Carrier were expensive.

 

The Wunda room stat I will use purely to view the house temp in the hallway (after it blew up my ASHP board!!!) (and er indoors will think that’s how you raise the temp ?)

 

I will use the command unit to act as the room stat (one zone whole of downstairs) and programme any heating times.

 

No need for the TP5000 room stat

 

TS715 time switch for DHW as per diagram (but will only use this if we go E7 or E10)

 

UFH pump will run from the buffer tank stat, this will mean the pump will only run when the buffer is up to temp. I can provide an override switch to this if I want to even out floor  temps. 

 

Not wiring for UFH  for cooling yet. Please let me know your thoughts , good or bad.

 

 

 

 

 

 

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@joe90 I guess you could use the ‘decorative’ wonda room stat (or at least a suitable 0v alternative) for cooling requirements in the future?

 

I’m not sure how you would ensure that you don’t have 2 stats competing (I.e. one calling for cool whilst the other was asking for heat)... but I doubt it would take much to make sure they call for service at different temps. 

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13 minutes ago, Gav_P said:

@joe90 I guess you could use the ‘decorative’ wonda room stat (or at least a suitable 0v alternative) for cooling requirements in the future?

 

I’m not sure how you would ensure that you don’t have 2 stats competing (I.e. one calling for cool whilst the other was asking for heat)... but I doubt it would take much to make sure they call for service at different temps. 

 

I believe the command unit also controls cooling if required, frankly I just want to get the heating sorted, I won’t need cooling till next year, if at all. @Gav_P did you get your control board yet?

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17 minutes ago, Gav_P said:

I’m not sure how you would ensure that you don’t have 2 stats competing (I.e. one calling for cool whilst the other was asking for heat)... but I doubt it would take much to make sure they call for service at different temps. 

 

The stats I used have a link internally to select whether they run in cooling mode or heating mode.  The display shows what they are doing (heating or cooling).  I fitted two, one above the other, on the hall wall, with the cooling stat normally set to call at 22.5 deg C and the heating stat set to call at 20 deg C.   I have occasionally turned the cooling stat up to 23 deg C, just to stop the cooling coming on in winter, but that's just two button presses.  The stats I used were the Computherm Q3RF ones, and are both battery powered remote control units.

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10 minutes ago, joe90 said:

 

I believe the command unit also controls cooling if required, frankly I just want to get the heating sorted, I won’t need cooling till next year, if at all. @Gav_P did you get your control board yet?

Ah that’s useful. 

 

No it hasn’t arrived yet, although I have been at work today so it may have turned up. However, I’m away for a week from tomorrow, so might struggle to fit it before I leave. 

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44 minutes ago, joe90 said:

I have ordered the Salus valve to fine control the manifold temperature, any thoughts on my plan above please.

 

I'm not 100% certain that you can mix dry contact control with control from the Command Unit, so it may be that the time switch may not work as planned.  The manual seems to imply that setting parameter 100 to 4 (air to water monobloc with command unit as thermostat) may disable the dry contacts, but it's far from clear if it disables all of them, including the terminal 13 (0V) to terminal 15 (DHW high temperature mode) or not.  Mine runs in system mode 2, air to water monobloc with climatic curve and control by dry contacts, and I don't use the connection to terminal 15, so I'm not able to test whether or not it works with the system mode set to 4.

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1 hour ago, JSHarris said:

I'm not 100% certain that you can mix dry contact control with control from the Command Unit, so it may be that the time switch may not work as planned.  The manual seems to imply that setting parameter 100 to 4 (air to water monobloc with command unit as thermostat) may disable the dry contacts, but it's far from clear if it disables all of them, including the terminal 13 (0V) to terminal 15 (DHW high temperature mode) or not.  Mine runs in system mode 2, air to water monobloc with climatic curve and control by dry contacts, and I don't use the connection to terminal 15, so I'm not able to test whether or not it works with the system mode set to 4.

 

As I understand it the command unit working as room stat and timer only work for heating and if I use E7 or E10 I will set the command units heating on times to match cheap electricity. The separate timer would be for DHW only.(or sanitary hot water as carrier call it) . If I use E7 or E10 I will set  this separate timer to also take advantage of cheap electricity. I can chose the two to not collide time wise.

 

Having read the installation manual again ?you can set the “heat water set point” as parameter 113 (heating only?) but there appears no “sanitary hot water set point”. So I guess the DHW cylinder stat will be a way of limiting this temperature?. Therefore I do wonder when the ASHP is trying to heat sanitary hot water it may go into defrost before the DHW tank is up to temp? Is it a case that the “heat water set point” controls both heating and sanitary hot water temps?.

 

I am beginning to understand this better but the more I understand the more questions I have!

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There is certainly some "interesting" logic applied by whoever programmed my LG ASHP.  I could have set the supplied controller to be my time switch if I wanted to (though it is fiendishly complicated and no "normal" functions like advance to next program, or boost)  But as soon as you enable the dry contact "thermostat" input, the internal timer is disabled and it just turns on and off according to the external thermostat.

 

So my heating is now controlled by a conventional central heating programmer that powers the UFH manifold controllers when heating is on, and the volt free "call for heat" contact on the  manifold controller connects to the ASHP dry contact thermostat input.

 

I now only use the supplied controller just for setting parameters etc, not as a controller.

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18 minutes ago, ProDave said:

I now only use the supplied controller just for setting parameters etc, not as a controller.

 

Is the heating water temp one of these parameters?, is the DHW temp another or the same.?

 

my controller does have “touch and go” buttons, home, away, sleep, next. (Yet to programme them yet).

Edited by joe90
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26 minutes ago, joe90 said:

 

As I understand it the command unit working as room stat and timer only work for heating and if I use E7 or E10 I will set the command units heating on times to match cheap electricity. The separate timer would be for DHW only.(or sanitary hot water as carrier call it) . If I use E7 or E10 I will set  this separate timer to also take advantage of cheap electricity. I can chose the two to not collide time wise.

 

Having read the installation manual again ?you can set the “heat water set point” as parameter 113 (heating only?) but there appears no “sanitary hot water set point”. So I guess the DHW cylinder stat will be a way of limiting this temperature?. Therefore I do wonder when the ASHP is trying to heat sanitary hot water it may go into defrost before the DHW tank is up to temp? Is it a case that the “heat water set point” controls both heating and sanitary hot water temps?.

 

I am beginning to understand this better but the more I understand the more questions I have!

 

 

You don't need a DHW stat, as the heat pump runs at a maximum of 60 deg C in DHW mode.  You can set the DHW temperature using parameter 113 on the command unit.  The default setting is 45 deg C.

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1 hour ago, JSHarris said:

You don't need a DHW stat, as the heat pump runs at a maximum of 60 deg C in DHW mode.  You can set the DHW temperature using parameter 113 on the command unit.  The default setting is 45 deg C.

 

Ah, my instructions say “113, heat water set point / this code is use to set the fixed heating water set point” min 20’, max 60’, default 45’

 

i read this as “heating” not “sanitary hot water”. Does the ASHP heat water to two different temps, heating and sanitary (DHW) or just one temp. There is no sanitary hot water temp setting in my instructions. 

 

My my brain hurts!.

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1 minute ago, joe90 said:

 

Ah, my instructions say “113, heat water set point / this code is use to set the fixed heating water set point” min 20’, max 60’, default 45’

 

i read this as “heating” not “sanitary hot water”. Does the ASHP heat water to two different temps, heating and sanitary (DHW) or just one temp. There is no sanitary hot water temp setting in my instructions. 

 

My my brain hurts!.

 

 

There are two separate settings, one for DHW that's a fixed flow temperature, set by parameter 113, the other a variable flow temperature for heating, set by the heat curve that parameter 112 refers to.  There are a range of pre-defined, numbered, heat curves that can be selected by parameter 112.  All offer weather compensation to different degrees, except for the case when parameter 112 is set to 0.  In this case the user defines a custom heat curve using the custom set points in parameters 119, 120 and 121 for heating.

 

For cooling using a custom curve then set parameter 117 to 0, then use parameters 122, 123, 124 and 125 to set the shape of the cooling curve.

 

The settings I use (just for heating and cooling, I don't use the DHW mode) are these, which fix the flow temperature at 40 deg C in heating mode and 12 deg C in cooling mode:

 

112 = 0

117 = 0

119 = 19

120 = 40

121 = 40

122 = 40

123 = 14

124 = 12

125 = 12

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19 minutes ago, JSHarris said:

 

 

There are two separate settings, one for DHW that's a fixed flow temperature, set by parameter 113, the other a variable flow temperature for heating, set by the heat curve that parameter 112 refers to.  There are a range of pre-defined, numbered, heat curves that can be selected by parameter 112.  All offer weather compensation to different degrees, except for the case when parameter 112 is set to 0.  In this case the user defines a custom heat curve using the custom set points in parameters 119, 120 and 121 for heating.

 

For cooling using a custom curve then set parameter 117 to 0, then use parameters 122, 123, 124 and 125 to set the shape of the cooling curve.

 

The settings I use (just for heating and cooling, I don't use the DHW mode) are these, which fix the flow temperature at 40 deg C in heating mode and 12 deg C in cooling mode:

 

112 = 0

117 = 0

119 = 19

120 = 40

121 = 40

122 = 40

123 = 14

124 = 12

125 = 12

 

Reading this, is there any wonder why most installers just stick these units in with default values and walk away.??!

 

There is a real market opportunity here for tuning ASHP installations properly .....

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