Fratelli TRV valve M28 x 1.5

JL2020

I am interested in fitting out my home with Tado smart trvs, i currently have Fratelli TRVs which I believe are an m28 x 1.5mm thread.

In your documentation, you state that these valves are not support with adapters, but other M28 x 1.5mm valves are. I would like to know why they are incompatible, do you have a dimensioned cross section of the M28 adapter, that i could reference to see if there is anything I can do to make the adapter work?

I am not able to change the TRVs in my house as I have 14 radiator, and the cost of this would be prohibitive when then combined with the costs of tado.

Thanks

JL2020

As an update to this request and for any future searches, I have installed the TRVs on my radiators, slight modifications were required. you need to open up the hole the radiator pin moves through on the adaptor slightly, and I have had to cut down the plastic push pins supplied - but with this change they work perfect.

this works for pettinaroli / fratelli TRV valves with M28 x 1.5 thread (my TRVs are connected to 10mm micro bore)

Jccool

Hello, I'm coming a bit late but I've got the same issue than you.

Would you be able to help me by sharing some pictures please

JL2020

hopefully the drawing makes sense. you need to open up the base housing that screws on to the fratelli thread - the fratelli pin then partially sits in this. Then i cut down the Tado pin to 8.47mm, and used that (as shown in blue) to make up the gap to the tado plunger.

Its important to not open up the hole too big, or the blue part will not be constrained very well.

I have been using mine for 18months now, works perfect - much better than replacing my TRVs

Jccool

Thank you for answering !

Unfortunately I'm still lost, but I really appreciated that you took the time to answer me.

 I bought an M28 M30 adapter.

But if I keep the piston of the adapter, I can't screw the adapter and if I remove the original one is too short.

Jccool

After a brain break, I was able to do it thank you !

Sirdigby

Hey guys,

So I've stumbled upon this thread, it may be my last hope.

I've cut down the pin, but what is meant by opening up the base housing that screws onto the Fratelli head?

I'm currently getting E4 error.

JL2020

You need to increase the internal diameter of the tado adapter slightly, so they radiator pin can sit comfortably within it

Rashidmk

@JL2020 Thank you! I am in the same situation as you were, and your workaround saved me. It works perfectly.

Pin was reduced to approx 8.47mm:

I drilled the hole of the Tado adapter with a 4.5mm bit so that the hole is widened and fits comfortably over the Fratelli TRV, you can verify by pushing the pin inside, it should be working easily without getting stuck or jammed:

Then you can insert the Tado pin so that it looks like this (Tado pin is held loosely inside and will fall if touched):

Then install the main base plate/adapter:

Final install should look like this:

After that, install the Tado Thermostat, it should calibrate automatically as soon as you fix it on.

Thanks again to @JL2020! you saved me a lot of work, frustration, time and money, really appreciated!

Tarantado

Is that the correct orientation? The head is outside?

JL2020

Out is better for thermal readings, most people don't have an option and they are installed vertically as all of mine are

Esteb

There is a German company that makes metal adapters for Pettinaroli M28x1.5mm to M30x1.5. They also have adapters for many other brands. You can buy them on Amazon, https://www.amazon.de/dp/B077GD1YJ6/ref=pe_27091401_487024491_TE_item

Check also their website:
https://eurotronic.org/produkte/kategorie/metalladapter/

Riccivi

Hello @Esteb,

Did you already tested this adapter ? I don’t know if it will resolve the problem

, I’m in the same situation. Thx

Esteb

Hey @Riccivi I have just ordered them and should get them this week. Will let you know.

Esteb

hi @Riccivi

Everything works perfectly, just be careful how you insert the pin, it should be inserted from the outside. First mount the adapter, then insert the pin, then mount the smart thermostat.