Excessive jitter on broadband connection

[#1]

Having replaced my ancient valliant boiler with a baxi, I also installed a baxi usense "smart" thermostat, Since that time I noticed not only excessive jitter on my connection and ping times out of the ark.

I seems, after much digging, that this little so and so is constantly polling the internet, not only for the outside temperature (irrelevant) since I have no outdoor sensor fitted. But also Baxi itself. Things have marginally inproved after the thermostat decided to update itself, but are still quite bad.

The moral here is that if your internet connection goes to the bad and you have co-incidentally fitted a new "smart" thermostat this may well be the culprit!

[#2]

Does the boiler still work with the smart thermostat if you <Disconnect> your modem's PPP connection to the internet ?

If the boiler does still work without the internet, then -

1) You might want to put your "smart" devices on a separate VLAN and control the access to the internet.

2) You could block the unwanted internet accesses by setting up a DNS blacklist, perhaps with Pi-hole, or OpenDNS, or editing your router's 'hosts' file.

3) If your router can do QoS then perhaps you could lower the priority of the polled packets - to reduce ping times and jitter.

If your boiler DOESN'T work without an internet connection, then good luck with that if your broadband ever plays up !

[#3]

Hi, Thanks for all these sugestions. No, These Baxi Usense thermostats will not work without an internet connection unless you use them in manual mode, which rather makes a mockery of fitting them in the first place, as a simple dumb " Twist and go" jobby will do just the same.

This if course makes a mockery of even fiiting these in the first place - £150-00+ for the Usense - £20-00 for the twist and go, not to mention the dreadful and absolutely useless MyBaxi app, which for some strange reason demands access to your contacts and photos, deeming this apparently essential to operate the boiler!

The line jitter, allowing for lag, exactly coincides with the polling interval of the Usense wi-fi module fitted to these things. I guess the only cure is to run this Usense thermostat in manual mode and switch off the internet access for it, uninstall the dreadful Mybaxi app and accept the fact that I have bought a turkey!

[#4]

@Moscarella  - I'd be looking at investing in 3rd party router if you're sure it's relating to network activity causing the jitter, ours is pretty stripped down with a very limited features to interact with. I'm assuming you're using ours or do you already have a 3rd party one?

[#5]

Hi, Thanks for the reply. I do use Plusnet router which has always behaved itself perfectly. Re: investing in another router., I suspect that this may well be good money after bad.

I think that I will probaby uninstall this piece of Baxi (Chinese made ) junk and replace it with something else. All the line problems started with the installation of this thermostat and will probably end when I remove it. If yiu would like a proper heads up on these problems, check out the baxi reviews on the google store platform....I am not alone!

[#6]

@Moscarella - Haha, this isn't a plug but I use Tado, I'm not bothered about a nice fancy display as I just like to keep heating at set scheduled temperature. Plus the Mrs won't have the option to spin the thermostat up to 30 degrease and leave it all day. I suppose it's only the same with a router, an awful lot of features that you don't really need to use and play with once it's working.

[#7]

Hi, This is what I meant by a "twist and go" thermostat, and yes absolutely, this is what I will be switching to or something similar.

Regards

[#8]

Hi, Re: your advice and observations on line jitter

jitter goes from 9.5 ms to 1ms with the thermostat blocked at the router
ping goes from 32ms down to 20ms (still awful) with the thermostat blocked at the router

I have been unable to locate a circuit diagram for the baxi usense, so it's all guesswork really, and I am absolutely certain there are a least several dozen people out there just itching to put me right!

As this is a chinese made item (cheaply made as possible) it would seem to be the good old 555 timer chip in bistable mode to produce a flip-flop type signal to poll the internet , when I get down to removing it I will power it up on the bench and see just what the scope/ logic probes say.

I suspect that the timer chip timings in this case cannot be adjusted by changing either of the resistors or the capacitor in the RC tank circuit as tthis part of the circuit is probaby missing altogether, this would only be needed to produce a high accuracy signal if the 555 is wired in astable mode, and as the line jitter appears to be unstable this would not be the case be if the RC tank circuit is present and in circuit.

All this is probably completely wrong and the whole shebang is running from a custom chip! Whatever it is, this I think has go to go..

[#9]

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@Moscarella wrote:

... I do use Plusnet router which has always behaved itself perfectly. Re: investing in another router., I suspect that this may well be good money after bad.

You can test your theory, by checking your Plusnet router's 'Bufferbloat' score here - https://www.waveform.com/tools/bufferbloat 

'Bufferbloat' is a good measurement of how your ping times are affected by traffic - such as the polls from your Baxi.

It is probably worth doing the test with the Baxi stuff disabled so as not to interfere with the measurement.

A decent router should give you a 'Grade A' or 'Grade A+' score.

Here's mine using a pfSense router with DrayTek Vigor 130 modem -

[#10]

Hi, Thanks for that, ran this test and apparently the only problem seems to be "Low Latency Gaming", As the closest thing on my systemto gaming  is Scrabble, I cannot see that as a problem. I do stand by my findings that the culprit is this pesky thermostat - jitter goes from 9.5 ms to 1ms with the thermostat blocked at the router and that's enough proof for me. Never had any problem with PN router until I installed this thermostat.

As this is a chinese made item (cheaply made as possible) it would seem to be the good old 555 timer chip in bistable mode to produce a flip-flop type signal to poll the internet , when I get down to removing it I will power it up on the bench and see just what the scope/ logic probes say.

I suspect that the timer chip timings in this case cannot be adjusted by changing either of the resistors or the capacitor in the RC tank circuit as tthis part of the circuit is probaby missing altogether, this would only be needed to produce a high accuracy signal if the 555 is wired in astable mode, and as the line jitter appears to be unstable this would not be the case be if the RC tank circuit is present and in circuit. but as the circuit board in this is mainly SM is It is going to be more trouble than it is worth.

All this is probably completely wrong and the whole shebang is running from a custom chip! Whatever it is, this I think has go and be replaced with a twist and go jobby and control the boiler functions from the boiler itself

[#11]

@Moscarella 

Whatever it is, this I think has go and be replaced with a twist and go jobby and control the boiler functions from the boiler itself

If you want a reasonably priced semi-smart thermostat , I've been using one of these https://www.amazon.co.uk/ESI-Innovation-Controls-Programmable-Thermostat/dp/B01N9X2F32 for a couple of years now with my Baxi 800.

It has no internet connectivity but is programmable with schedules, has TPI & Optimum start/Stop functionality and away mode. It can connect to the boiler either as on/off or Opentherm ( mines just on/off ).

[#12]

Hi, Many thanks for that recommendation. I have put thison my list of recommendations from actual users. I hope to get the replacement sorted before I junk a £150-00 thermostat. Fell into the trap of this useless Usense and the equally useless mybaxi app ecause I foolishly thought it would all work together seamlessly....I got that wrong!

Best Regards