Vaillant ecotec plus 418. Many problems.

[EricTheFedUp]

Due to the government puahin up rent prices my housing association
now have a surplus of cash and are replacing the boilers with new
ones. My old boiler was brilliant everytime they serviced it they said
how efficient it was.

I found this thread //www.diynot.com/diy/threads/new-vaillant-ecotec-plus-418-hot-water-not-hot-enough.233250/
and can see some of the ideas given but mine is slightly different.
You may want to get a flask and dandwiches for this.


Where to start? It was only fitted a couple of months ago and until
recently we had it on hot water only. The water didnt seem as hot as
before and also seemed to take longer to get hot water to the taps.
Just put it down to the temperature monitors being different.
I thought the pump in the airing cupboard seemed to be running a lot
longer than it used to also.

Then i switched it onto heating as well as hot water and things went really
badly. No heat unless you switch the hotwater off. So we can have one or
the other.

The pump runs for hours and hours after the water has heated. The engineer
said no its only 20 minutes and then muttered about the heating being on
and would not listen to me when i said the hot water heated for 20 minutes or
so and then went off and then back on again 2 minutes later which it then
repeats randomly. He said it depends on the efficiency etc. Our system is
very efficient and it didnt take hours to heat the water or for the boiler to
keep kicking in and out every few minutes with the old boiler.

He said its the electric valve that switches from water to heating and both
blamed it on the snapped indicator arm which was broken when it was
new but as its just an indicator and still visible it never caused any issues.

One day the heating didnt cut off at 18 degrees as set by the stat, it was
getting close to 25 degrees and the boiler was still heating. (set to heating
only).

They changed the tank temp sender and now they have changed the valve also
but it still doesnt work.

I currently have the hot water off and the heating on timed, and have to switch
the water on between the heating times.
Even this doesnt work properly....aghhhhh.

Heating switched off at 10:30pm. Midnight the pumps still running. I moved the
switch to off not timed and the pump went off after a little while. I moved it back
to timed and the pump stayed off.

2:20am the pump kicks in.... why?? the heating is on timed to start at 6:30 and
the hot water is off.

We have had the S35 or 53 code i forget which the missus has it written down.
This was just after they fitted the boiler.
Not checked it recently.

After finding some threads on here and another foru, i changed the pump timer
to 5 minutes not 20 and the heating down to 12 not 18. This did help with the
time the pump ran for. still ran excessively but less often.
In anticipation of their visit i reset them. I dont want them blaming me.

Sorry for the war and peace edition but this is now getting beyond a joke, I cannot
afford for the pump and boiler to be running all the time.


Many Thanks
Eric

 

[EricTheFedUp]

Sorry for the long thread, basic jist....

heating didnt switch off at set temp, new thermo fitted (didnt work)
cannot have water and heating on at same time, new valve fitted (didnt work)

pump is on setting 3 and runs for HOURS.... even on hot water alone and even
when heating and water are off. It switched on at 2am for no reason?

Thanks
Eric.

 

[Agile]

I would expect the main problem is associated with temperatures. Search here for more info.

But there does seem to be a wiring fault too as you should normally be able to have heating and hot water on together.

Tony

 

[EricTheFedUp]

What would cause the pump to kick in even though it was 3 hours after the water and heating were
switched off? Water off at the switch and heating on timed but not due to switch on for another
3.5 hours.

Pump switched on and ran for just under 10 minutes, not sure of the boiler kicked in as i was
in the bathroom at the time and could not check.

Another thing that i didnt mention is that one night i switched the hotwater on after the heating
had switched off. I ran it for 30 - 40 minutes and switched it off.

The pump ran on for a while and just before it stopped the radiators got warm also?
This was after they replaced the electric distribution valve? the one in the airing cupboard.

What have they dont to our once efficient heating system?

Thanks

 

[scoobydo123]

What controls do you have? Maybe the anti legionaires kicked in?

 

[EricTheFedUp]

Siemens RWB2007 and a Siemens thermostat.

 

[scoobydo123]

ok so forget what I just said as not the advanced controls. Sounds very much like a simple wiring fault or the programmers acting up. What flow temp you set to Also model of roomstat

 

[EricTheFedUp]

Roomstat just has frost (star) then 10 - 30 with e small thermometer symbol near the 30 no other markings.

I set the water and heating temps from 60 - 70 and that makes no difference to the way it behaves.

Dropping the afterrun time from 20 minutes down to 5 minutes and dropping the kw from 18 to 12
did seem to improve matters but it still kept kicking in and the pump runs on for hours after it
should.

 

[scoobydo123]

Is you pump on 3? What S codes are displayed when playing up? Are the valves on the pump fully opened? By afterun time I guess you are talking about pump overrun 20 is the default for the anticycle timer. Setting the water temp tap sign has no bearing on your install. Set D.0 to 8 do you get a long burn then? How many radiators do you have and is it microbore. When it fires up how quick does the temp rise view d.40 and d.41 do you get a nice long burn before it cycles. Have you a balance valve for the DHW cyinder. Think if s53 is displayed then boiler will run to try and get rid of surplus heat. Sounding like mike have circulation issues but need the questions answered

 

[EricTheFedUp]

Yes pump is on 3, Yes pump overrun was set to 20 minutes but it ran for much much
longer, over 3 hours non stop with just the hot water on and heating switched off.
I manually turned it off after 3 hours.

I did woder about the top dial marked with a tap, i switched the lower one off and the
boiler turned off completely. I think thats normal but wasnt sure if the top one did anything
at all?

What should the temp be on the boiler when its idle with heating and water off?

What does a balance valve look like? Red plunger with markings?

D40 / 41 23 / 25 before switching the heating on, approx 10 seconds before
the flame symbol appeared. pump was already running despite the
house being above the stat temp anyway.

thanks.

 

[scoobydo123]

so what happens if you turn down stat on cylinder? What are the scodes whilst the boiler is running the pump? Flow temp this time of year should be set to around 70.

 

[EricTheFedUp]

They replaced the stat and it made no difference to the issues. changing the
valve seems to have caused more problems.

No difference if we set the temp to 60 or 80+ on the tank.

House was built in the late 90's and its warm now with the heating off, TV and
computer giving off enough heat for me to be sitting in a T-Shirt now.

thanks

 

[scoobydo123]

so you have had work done that has not fixed the issue? Did you pay for this work. Sounds like wiring issue but

 

[simond]

It is a housing association property. The electrician would not understand boilers and the heating installer wont understand 3 port wiring - so they keep changing parts.

Par for the course I'm afraid; in your sector few technicians are either motivated or particularly bright.

 

[Bunnyman]

Why blame the boiler u have system fault?