Gradual valve closing process is noisy
Hello,
I own a thermostat with a relay and several valves. When a certain temperature is manually commanded in a room, the thermostat starts the boiler and the commanded valve opens. That is obviously fine.
But when the room is about to reach the target temperature, the valve starts a gradual closing process in two steps: it closes a little, wait a few minutes, and then closes completely. The problem is that, in this condition, the heating system is restricted to that room and maybe a few other uncontrolled radiators. Therefore, the pressure in the system is relatively high, and so, when the valve partially closes, a noticeable hissing noise can be heard during those minutes until it closes completely. This can be quite significant in a bedroom at night.
Could it be possible to add a function/parameter in the app to change that behaviour and close the valve in a single step when the commanded temperature is reached? I think that progressive closing feature has no particular interest (a so-precise control of the system is not needed) and can be quite disturbing.
Thanks!
Comments
6 comments
Hello,
I have the same issue. When the temperature reaches the setpoint, the valve stays in a middle position. At that moment, the noise from the radiator is so loud that we prefer not to heat the bedroom at all.
I agree with dariocs and would like to ask whether it could be possible, in the app, to solve this issue by:
adding a parameter to the valve to choose an ON/OFF mode, in order to forbid the middle position
or
adding a parameter to define the middle position, from 0% to 100% of the full valve travel
Before writing this message, I tried many things:
reducing the pump flow rate (this impacts all radiators in the house and reduces the heating capacity),
reducing the flow rate on the individual radiator valve (this does not solve the issue because the random number of open radiators in the house creates a very wide dynamic range of flow rates),
adding glycol to increase the water viscosity (made it worse),
adding a differential pressure valve to control the differential pressure (same result as reducing the pump flow rate).
The next thing I plan to try is to replace the Netatmo valve in the bedroom with a manual valve.
Hi, I have the same problem at my house. I've partially solved it by loosening the valve a little; it went from a clear whistling sound to a more acceptable flow sound...
I also think it's pointless for the valve to close almost 90% when the set temperature is approaching. It should close completely when the system calculates that the radiator's inertia will reach the set temperature. It's simple and would extend the system's lifespan. I don't understand how it works, and it seems like no one from Netatmo is explaining anything.
Regards, David
Thank you, kapytan, for your feedback and experience.
I’m not really a fan of the solution you’re proposing because:
slightly unscrewing the valve (after calibration) no longer guarantees that it is fully open, so you are probably losing some heating power
every time you change the batteries, you have to readjust the valve, recalibrate it, and then unscrew it again. With rechargeable batteries that have a high self-discharge rate, I have to replace them every 2 to 3 weeks, and this procedure adds extra hassle to the already annoying “battery replacement” task.
I found a “Netatmo-based” solution that perfectly solves the problem (provided you have access to your pipes in a concealed location):
I removed the Netatmo valve head from the radiator and replaced it with a fully open lockshield valve.
Then I used a Netatmo relay and thermostat to control a motorized valve.
This motorized valve is what actually controls the water flow through the radiator.
Since Netatmo thermostats work in ON/OFF mode, I no longer have any issues.
Advantages:
no more whistling noise in my radiator
I can benefit from “advanced” regulation (PID control from the thermostat)
the thermostat is located in the middle of the room, so the controlled temperature is closer to the perceived comfort level
Disadvantages:
you need enough space to hide the motorized valve
it is somewhat expensive
since the Netatmo relay only provides a NO contact, I have to use a contactor with both NC and NO contacts driven by the relay, or use a normally-closed valve with an automatic return ensured by a capacitor
My overall opinion on the Netatmo solution:
Netatmo radiator valves:
they could include a small solar panel; even if it wouldn’t cover all energy needs, it could cover part of them and extend the recharge interval of rechargeable batteries. An autonomy of 2–3 weeks is far too short
it should be possible to choose the intermediate position used when the measured temperature equals the setpoint, or at least to choose a pure ON/OFF mode without this intermediate position
it would also be nice if a radiator valve could be directly controlled by a Netatmo thermostat
Netatmo relay:
they could have provided a 3-wire output (NC/NO), especially given the price of the thermostat… I would gladly have paid €2 more. Finding an NC/NO contactor in a compact module to avoid using a DIN enclosure is not easy, and the solution using a normally-closed valve with automatic return is more expensive and slightly less reliable.
About the Netatmo app:
I used a Domoticz server for a long time, and I still keep an eye on solutions like Jeedom with very interesting components from the Shelly brand. These are much more open and DIY-oriented solutions. It’s not exactly the same target audience, but inevitably I find the Netatmo solution too closed. It does have the advantage of being reliable and simple, which is a plus if I ever want to sell my house or allow family members to be autonomous in my absence. However, like many large-company apps, I find that they are slow to integrate essential features.
Thanks for the responses, guys.
Sylvain, what you propose will definitely work, but I find it too complex and expensive. From my point of view, the whole point of this system is to be a packed "simple" solution for the heating needs. I think it could work enough just by allowing each radiator valve to work in pure on/off mode (as you also suggests).
I totally agree on the annoying battery replacement process (sometimes it does not connect again, sometimes it does not calibrate...)
By the way, which rechargeable batteries do you use? My Eneloops just don't have enough voltage to make the valve work.
I understand that what I’m proposing may be considered too complex and too expensive. However, at the moment the whistling noise wakes me up every night when the radiator regulates around the ambient temperature… this is no longer acceptable.
I am using standard NiMH rechargeable batteries with a nominal voltage of 1.2 V. You must not wait until the valves stop responding before recharging them. At that point, it is already too late. Why? Because NiMH batteries do not tolerate deep discharge, unlike other technologies such as NiCd.
The valves consume very little power, so when they are no longer even able to communicate, it means the batteries are completely depleted and have been deeply discharged.
This therefore requires a certain level of discipline. Here again, Netatmo valve heads could offer more precise battery voltage monitoring to better indicate when recharging is needed. They are very likely equipped with an ADC capable of accessing this information… once again, this would only require a software/firmware update.
If you want, you can try 1.5 V lithium batteries from Delyeepow. Like all lithium batteries, they include a BMS that cuts off the discharge to protect against deep discharge. The issue remains somewhat similar, though: the valve’s power consumption is extremely low, and the BMS is probably not designed for this type of discharge profile. As a result, I believe the risk of damaging the battery through deep discharge is comparable to that of NiMH cells.
The main advantage is that you benefit from a higher voltage.
Thanks, I will try the lithium ones. The Eneloops simply do not work, even after a full recharge (probably the 1.2 V nominal voltage is too low for the valve).
Anyway, going back to the main topic. Is there any Netatmo representative in this forum who can help with the noise topic? Or at least recognize they are aware of the issue?
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