Carel controller settings

[Marvin]

Hi

I need to change the set temperature of my hot water tank using the Carel controller.  I have the engineering code but cannot find the location where you set the hot water temperature thermostat. Its slightly too low at present. 

 

Does anyone know the system well enough to guide me?

 

 

[dpmiller]

which machine, and do you mean the actual setpoint or do you want to recalibrate the probe?

[Marvin]

Hi @dpmiller

 

Hi Its the CE-iVT9 and it's the set point? (to be clear - the point at which the water in the hot water tank rises so much that the ASHP stops heating the water in said tank)

[Bramco]

You can do that on the app - it's on the main page just use the + or - buttons to increase it or decrease it.

[Marvin]

We have no app connection....

 

[dpmiller]

User Mask, unless you're using time controls in which case it's in Timezone

[Marvin]

Hi @dpmiller

 

Yes I can bring it to user mask but then what? I have previously entered the engineers code but I cannot access U01

[Marvin]

Hi @dpmiller

 

I think I have worked it out. I use weather compensation so the hot water temperature is defined there.

[Marvin]

My problem has been that the hot water temperature has been set at 40 but it doesn't actually kick in until about 36 which is too low. So on the odd occasions when the temperature is below 40 and there is shower demand the water is not hot enough. However because I have the system running on low speed mode it takes a while to reach 40 so rather than enter the weather compensation part I will alter the hot water temp diff to 2 and the stop to 2 and see how that works out.

 

Unless anyone has a better idea....

 

Thanks

 

Marvin 

[Marvin]

I cannot find the hot water set points so have adjusted the temperatures in the weather compensation section.

M

[HughF]

Sorry, not in front of mine at the moment. I can upload the manual when I’m home later though.

[HughF]

It should be on page 2 of the user mask settings. I run weather comp (fan mode = eco) but not for hot water and the settings in user mask take precedence.

[JohnMo]

Just looked on Cool Energy website full manual is available to download. 

[dpmiller]

 temp difference= hysteresis. reduce that a bit it'll cut back in sooner

stop temp difference is an allowed overshoot, more useful for heating as gives more time for the unit to ramp down without shutting off immediately

[HughF]

I run temp diff of 12.5 and stop temp of +4 iirc…

[dpmiller]

Mine's a bit different as I'm heating a TS and the probe is halfway down to hold a body of water at temperature- setpoint 50, difference 1.0, stop 0.5. This actually means the top of the tank ends up at 55 (5c Dt), but the HP cuts in before DHW cools off appreciably for more-or-less continuous hot water *or* a reheat cycle of about 30mins each time.

[JohnMo]

1 minute ago, dpmiller said:

Mine's a bit different as I'm heating a TS and the probe is halfway down to hold a body of water at temperature- setpoint 50, difference 1.0, stop 0.5. This actually means the top of the tank ends up at 55 (5c Dt), but the HP cuts in before DHW cools off appreciably for more-or-less continuous hot water *or* a reheat cycle of about 30mins each time.

What sort of cop do you get doing a TS, how many reheat does it do a day. Do you draw you CH water from there also?

[HughF]

35 minutes ago, dpmiller said:

Mine's a bit different as I'm heating a TS and the probe is halfway down to hold a body of water at temperature- setpoint 50, difference 1.0, stop 0.5. This actually means the top of the tank ends up at 55 (5c Dt), but the HP cuts in before DHW cools off appreciably for more-or-less continuous hot water *or* a reheat cycle of about 30mins each time.

TS with a sanitary coil, tank-in-tank, or PHE?

[Marvin]

53 minutes ago, dpmiller said:

Mine's a bit different as I'm heating a TS and the probe is halfway down to hold a body of water at temperature- setpoint 50, difference 1.0, stop 0.5. This actually means the top of the tank ends up at 55 (5c Dt), but the HP cuts in before DHW cools off appreciably for more-or-less continuous hot water *or* a reheat cycle of about 30mins each time.

This is the sort of thing that is my aim. I just need to adjust the ASHP controller to the right settings.

[HughF]

15 hours ago, Marvin said:

My problem has been that the hot water temperature has been set at 40 but it doesn't actually kick in until about 36 which is too low. So on the odd occasions when the temperature is below 40 and there is shower demand the water is not hot enough. However because I have the system running on low speed mode it takes a while to reach 40 so rather than enter the weather compensation part I will alter the hot water temp diff to 2 and the stop to 2 and see how that works out.

 

Unless anyone has a better idea....

 

Thanks

 

Marvin 

Umm, set your hot water at a higher temperature? I use the heat pump to heat to 50 and the upper immersion to heat the tank to 65. High hot water consumption in this house.

[JohnMo]

16 hours ago, Marvin said:

set at 40 but it doesn't actually kick in until about 36 which is too low.

Would have said 40 is very low, we just heat ours to 50 still get a CoP of 3.5 to 4 depending on temperature at start of heating. Your family must think ASHP equals luke warm water.

 

From a health perspective 40 is the ideal temperature for legionella to grow, so way from optimal. You really need minimum of 45 then it's dormant.

[dpmiller]

2 hours ago, JohnMo said:

What sort of cop do you get doing a TS, how many reheat does it do a day. Do you draw you CH water from there also?

Never bothered to calculate it tbh as it's a faff with no heat meter. We're on an E7 tarrif and timings are suited to this- just over half our total consumption is overnight. YMMV

It's a Worldheat 270l cylinder with two 3m2 coils- bottom for ASHP and top for DHW. I've also got a boiler stove to the body of the TS. Two immersions, both on a diverter. House is a mix of UVH and rads, two TMV manifolds.

But... ALL ASHP flow passes through the bottom coil so the TS plays like a big buffer tank- even with DHW heating turned off on the controller, in the winter the tank would stabilise at about 40c/ whatever the heating flow temp is at that time.

I do run the diverter on Boost for an hour in the mornings- this stops defrosts during the early morning underfloor heat periods as the system doesn't have to switch to the higher setpoint and negates some of the COP loss. Worth noting that an advantage of the CE diverter over the previous iBoost for this is that the CE one *only* boosts the upper immersion whereas the iBoost would have swapped down to the lower one once the top was satisfied. I don't even disable the boost in the summer now as if the tank is still hot overnight, no boost actually happens...

 

Daily reheats varies massively on the weather- a bit of sun and the top of the tank is at 65 or more, full summers day and whole tank is at 90. Could be no reheats during the day, or three or four.

 

For the first couple of years I did monitor daily and overnight consumption closely but can't be bothered now as the house is toasty all the time and the bills are barely more than for our previous house which was a third of the size. Something like 2000kWh for all heating and hot water during the winter quarter.

[Marvin]

Hi @JohnMo and @HughF

 

Thanks for your thoughts. 

 

4 hours ago, HughF said:

Umm, set your hot water at a higher temperature? I use the heat pump to heat to 50 and the upper immersion to heat the tank to 65. High hot water consumption in this house.

Yes I have lifted the sensor temperature to 42 degrees. However this is not the temperature of the water in the majority of the tank because of the sensor positioning. Reasonable hot water temperature and consumption in this bungalow.

 

 

 

3 hours ago, JohnMo said:

From a health perspective 40 is the ideal temperature for legionella to grow, so way from optimal. You really need minimum of 45 then it's dormant.

Thanks for your concern. Definitely over 45 degrees in majority of the tank when set at 42 and over 60 once a month.