Drayton Wiser - Hints and Tips Thread
Discussion
I'm far from a a boiler expert but I do wonder if the plumber meant to say that oil fired boilers don't modulate like newer gas boilers do.
You would think that an oil boiler must be looking at return flow temps as part of its control process. Not doing so would seem rather dangerous. Thus heating 5 rads will use more oil than heating just 1.
You would think that an oil boiler must be looking at return flow temps as part of its control process. Not doing so would seem rather dangerous. Thus heating 5 rads will use more oil than heating just 1.
AW10 said:
I'm far from a a boiler expert but I do wonder if the plumber meant to say that oil fired boilers don't modulate like newer gas boilers do.
You would think that an oil boiler must be looking at return flow temps as part of its control process. Not doing so would seem rather dangerous. Thus heating 5 rads will use more oil than heating just 1.
Sorry yes, I meant modulate not regulate. You would think that an oil boiler must be looking at return flow temps as part of its control process. Not doing so would seem rather dangerous. Thus heating 5 rads will use more oil than heating just 1.
Ours absolutely looks and flow and return temps, which is why getting the boiler temp right, rads balanced etc will help it run most efficiently with reduced cycling.
Anyone know if you can correct the "smart TRV's" temperature wise?
For 9 of the rads the "Wiser App" displayed room temp is pretty accurate (within 0.5 deg)
However for two TRV's displayed in the App they are miles out
One in the study is 3.0 Degrees lower than room temp - so stays heating for way longer than it should (small room loses temp quickly but heats up fast too)
The other in in a bathroom and reads 2.0 Deg higher than it is so shuts off too early?
For 9 of the rads the "Wiser App" displayed room temp is pretty accurate (within 0.5 deg)
However for two TRV's displayed in the App they are miles out
One in the study is 3.0 Degrees lower than room temp - so stays heating for way longer than it should (small room loses temp quickly but heats up fast too)
The other in in a bathroom and reads 2.0 Deg higher than it is so shuts off too early?
I would swap the ones that are misreading with some that aren't. That way you can check they are being odd. If they are, get them swapped with the seller. If they aren't then the layout of the room is probably causing a large heat difference - you could use one of the battery thermostats which then overrides the TRVs in the room.
ewanjp said:
I would swap the ones that are misreading with some that aren't. That way you can check they are being odd. If they are, get them swapped with the seller. If they aren't then the layout of the room is probably causing a large heat difference - you could use one of the battery thermostats which then overrides the TRVs in the room.
...you could use one of the battery thermostats which then overrides the TRVs in the room.
At around £80 for a room stat that's a significant expense to "fix" the inaccuracy ...you could use one of the battery thermostats which then overrides the TRVs in the room.
S6PNJ said:
Or simply set them for different temperatures taking into account their inaccuracy.
That's what I have done - however it means if I want to change the heating time on for all the upstairs rooms (copy schedule change on one room to 4 others) it means I have to go back and manually adjust to compensate for the error on the room with a big differentialActually I've got two TRV's that I haven't fitted yet so I might try them and see if they are more accurate - good plan
ewanjp said:
Interesting, won't the temp the rad gets to be limited by the boiler thermostat ....
If running a reduced load (warmer or less rads) the boiler output will reduce.A modern boiler with start by throttling the flame size, which is called modulation, which might alone be enough.
But if the boiler cant modulate low enough, or if the boiler is older and cant modulate, it will shut the flame/burner off completely once the flow temp is reached, and then cycle on and off. In effect very slow speed pulse width modulation to use a term from the electronics industry.
This cycling can increase wear on the boiler, or be less efficient, and a oil boiler which can reduce its output at all, running a single radiator (and perhaps not much pipework either) would be an extreme case you might want to avoid.
Not an expert on oil burners, but I also believe some oil boilers also allow manual flame size adjustments within the boiler itself, so you can reduce the output in summer for instance when just heating hot water.
I've been having a play with Home Assistant and the Wiser integration written by a HA community member. More on that another time maybe, once I've got the hang of it.
While reading through the support thread on the HA forums I found a post mentioning a Schnieder run Wiser forum. That's right, a Schnieder run, Wiser forum. I was none the wiser either (see what I did there
).
And sure enough >> here it is <<
No idea if its any good but I've already spotted posts about inaccurate trv temperatures and the boiler firing inefficiently which suggests others have similar problems to those reported here. Unless, off course, you lot are on there already
While reading through the support thread on the HA forums I found a post mentioning a Schnieder run Wiser forum. That's right, a Schnieder run, Wiser forum. I was none the wiser either (see what I did there
).And sure enough >> here it is <<
No idea if its any good but I've already spotted posts about inaccurate trv temperatures and the boiler firing inefficiently which suggests others have similar problems to those reported here. Unless, off course, you lot are on there already
The temperature read by a trv is never going to be 100% representative of the room temperature. It's attached right next to the heat source, quite often in a corner or behind furniture etc.
Some previous standalone electronic trv's I had did have a temperature offset function. It would be a useful addition on the wiser system.
Some previous standalone electronic trv's I had did have a temperature offset function. It would be a useful addition on the wiser system.
Joe M said:
The temperature read by a trv is never going to be 100% representative of the room temperature. It's attached right next to the heat source, quite often in a corner or behind furniture etc.
Very much this. I went through support around TRV inaccuracy last year and this was their (not brilliantly worded) response:Wiser Support said:
To put it bluntly, the fact is that raw temperature sensors can read upwards of 30C when the radiator is on would make the radiator thermostats behave irregular. Lets, for example, take the view that it measures accurately at the source and measures like a room thermostat, the radiator will be OFF most of the time as it will be hot next to the radiator, and in turn, will not further open the valve and it will be virtually cold in the room.
Furthermore, a room will never have an exact temperature per say, temperatures can fluctuate across a room itself will vary by 3-5C, from one corner to another. Even from the floor to the ceiling, the air has a different temperature and will be different. Even when you touch and handle the room thermostat or a radiator thermostat can play a part in temperature estimation.
With that said an estimator is a better and more accurate way of predicting the temperature of the middle of the room. Going forward, our tests consisted of various, capture information, simulations, white room testing and trials. The estimator was built from a collection of many data sets that showed typical responses of room thermostats to peoples rooms and an attempted best fit was given the accordingly to variability of all the environments but fundamentally its a difficult question, what temperature do you want to display on an iTRV that is warmed up next to a radiator?
The fact you see a difference of temperature of the room thermostat and the radiator thermostat is expected and even our competitors have similar system design when it comes to radiator thermostat estimation.
Furthermore, a room will never have an exact temperature per say, temperatures can fluctuate across a room itself will vary by 3-5C, from one corner to another. Even from the floor to the ceiling, the air has a different temperature and will be different. Even when you touch and handle the room thermostat or a radiator thermostat can play a part in temperature estimation.
With that said an estimator is a better and more accurate way of predicting the temperature of the middle of the room. Going forward, our tests consisted of various, capture information, simulations, white room testing and trials. The estimator was built from a collection of many data sets that showed typical responses of room thermostats to peoples rooms and an attempted best fit was given the accordingly to variability of all the environments but fundamentally its a difficult question, what temperature do you want to display on an iTRV that is warmed up next to a radiator?
The fact you see a difference of temperature of the room thermostat and the radiator thermostat is expected and even our competitors have similar system design when it comes to radiator thermostat estimation.
Just playing around with the app - I want to double check that the system is in oil mode as I kind of feel it's firing up more than the three times an hour it should be.
When I click on device details and then click on the HubR I can select to edit the heat source type, but this always seems to produce a list that shows 'gas'. So either the system isn't in oil mode or it was coded in such a way that the gas option always appears at the top of the list regardless of what is selected (if I were coded i'd show the option selected when you click on edit).
Can someone else with a non gas boiler have a look to see what theirs says when you select it?
I assume there isn't another way to find out what mode it's in. Rinsing through oil so I wonder if the new Wiser stuff is to blame...
When I click on device details and then click on the HubR I can select to edit the heat source type, but this always seems to produce a list that shows 'gas'. So either the system isn't in oil mode or it was coded in such a way that the gas option always appears at the top of the list regardless of what is selected (if I were coded i'd show the option selected when you click on edit).
Can someone else with a non gas boiler have a look to see what theirs says when you select it?
I assume there isn't another way to find out what mode it's in. Rinsing through oil so I wonder if the new Wiser stuff is to blame...
It's a known fault with the most recent version of the app - see here for some more info / details https://community.se.com/t5/Schneider-Electric-Wis...
If you have selected oil, then it 'disappears' a few moments later or goes back to showing gas, there is probably a good chance that it has actually set oil, but is just not showing it. I'm hoping that a new version of the app will sort this issue.
If you have selected oil, then it 'disappears' a few moments later or goes back to showing gas, there is probably a good chance that it has actually set oil, but is just not showing it. I'm hoping that a new version of the app will sort this issue.
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