vaillant ecotec plus 428, VR65 and vrt360f issues

[ferris]

Hi, please help!

I have just had a vaillant EcoTEC Plus 428 boiler fitted to a old system in my new house. the 25 year old potterton was on its last legs, at the same time a new twin coil DHW tank fitted into the loft (twin coil for the old solar system).

I requested a wireless VRT360f timer as I am used to this from my old property. the fitter also fitted a VR65 to hook the whole lot up.

now this has been fitted against my better judgement over the christmas period, three days before christmas eve fitting the boiler a new tank and systems and a day after to hook up the solar system to a new pump station.

everything was sort of okay over christmas eve to boxing day period, I say this as the boiler seemed to be on and off a bit, hot water was fine but the heating sort of needed a 'push' to get it up to temperature, but all the electronics seems to work fine. fitter turned the 28kw down to 8kw

now since the fitter has been back to sort the solar system out and 'tidy' the wiring he has left me with a fully manual system - i only noticed this after he had left and now he says he cant help and has arranged a vailliant service call. he turned the boiler up to 20kw - seems about right from what I have read on this site for 13 rads (?).

now since he left on Monday the controls on the VRT360f are dead, and as I said above I am opening and closing the valves manually, the boiler and pump seem fine. i have a flashing green light in the VR65 which means it has a com's issue, I have replaced the rubbish cabling between the boiler and the pump/VR65 with a new 5 core as the original was various odds and sods of cabling that was originally in place. yesterday I replaced the VR65 and still the same, so this pointing to be either the boiler or the 360 programmer.

the Vaillant guy is coming on Tuesday, but I would like to make sure everything else is fine and the fitter has not missed anything silly, and would love get my heating back to auto.

any thoughts out there, any advice would be much appreciated..

cheers and have a good new year

 

[gas4you]

The connections between the boiler, 360f and VR65 should be by twin core 0.75mm cable only connected to the ebus circuit.

The pump and valves should be 240V.

The ebus connections can occur at any point in the chain.

Have you tried turning off all power to the VR65? It should be fitted with its own switched fuse outlet, fused at 3 amp.

 

[ferris]

Hi,

yes thats all okay and done everything as you have said already.

Ferris

 

[gas4you]

Could be the VR65 gone down then. I've had a couple faulty out of the box, hence why the Vaillant rep always kept me supplied with a free spare, when I used to fit Vaillants.

 

[ferris]

yep tried that. I bought another one yesterday based on a thread on this forum and thoughts from my fitter.

I have just double checked the 5core that I used to run a new line, its 1mm not 0.75 as you mentioned do you think it could be the issue? before I ran this new complete line (measuring c22m running from garage to loft space), my fitter used a combination of the old cabling and new he had added in the loft...

Ferris

 

[gas4you]

1.0mm will be ok.

If I remember correctly, somewhere in the MI's it states that any length of ebus over 10M, the ebus cable must be seperate from any mains cable.

I cannot remember the distance between the 2 needed, but if you have used 22m of 5 core for both jobs, it could possibly be causing interference.

 

[ferris]

now that sounds interesting... the fitter just tidyied up the wiring which included adding a junction box with all the wiring coming together, he was using a pair of 3cores up to the loft and joining together again with some more 5core, since the tidy its not worked. i will try a new temp run in through the window and loft hatch.

thanks for the advice, ps what does MI mean and were is this info?

Ferris

 

[griggs]

thanks for the advice, ps what does MI mean and were is this info?

Ferris

Manufacturers Instructions. You should have been left a copy.

 

[Tipper]

MI's are available on the Vaillant website if you don't have them.

The 360f is a bit of a beast to set up. Not sure how it interacts with the 65 as my combi doesn't need one.

For best house temperature control I selected 'analogue' rather than 2-point. This modulates the water flow temp to suit the house demand but I don't know if this is the same on your boiler.

 

[ferris]

The 360f is a bit of a beast to set up. Not sure how it interacts with the 65 as my combi doesn't need one.

For best house temperature control I selected 'analogue' rather than 2-point. This modulates the water flow temp to suit the house demand but I don't know if this is the same on your boiler.

I am fine with the 360 as I got my head around it on a 340 we had in our old house. VR65 just sort of connects everything up together really.

sorry I dont understand the 'analogue' rather than 2-point.' bit, can you explain?

 

[Tipper]

One of the set-up items, page 39 in my litle book, gives the option of two point or analogue operation.

My understanding, after quizing those in the know on here, is that it allows the 360f to fully modulate the CH flow temp to suit the house thermal demand rather than an on/off control input to boiler firing up to the boiler set temperature. This is done by the (wireless) connection to the control ebus and it varies the boiler firing based on circulating water temperature sensing. It is supposed to give best economy.

When I ran my 937 on two-point it cycled alot and because of the anti-cycling timer, factory set to 20 mins, the radiators went cold all the time and the house took half the day to reach the set temperature! Analogue works much better.

BTW flat batteries don't help either! (No battery warning signal came up on mine on Christmas morning but new batteries fixed it!)

 

[ferris]

Okay, i have run a completly sperate 0.75 two core for the signal from the boiler to the VR65, still dead/flashing green light in the VR65...

I have just changed the setting to 'analogue' as you have described. Batteries now changed and still dead...

my thinking it mast be the boiler or the 360f receiver that is faulty, any other thoughts or areas to try??

cheers,

Ferris

 

[gas4you]

Is the flashing light on the VR65 fast or slow flashing.

If it is slow it is a comms error, if it is fast it says it is a short in the HW NTC .

Have you had a NTC fitted for the HW cylinder or just using a stat?

 

[ferris]

its slow flash, and there is no NTC fitted.

 

[gas4you]

Then sadly it appears you will have to wait on the group service engineer attending.