Help Required - Vaillant Ecotec Pro 28

[jacknicmeg]

Hi,

I have a Vaillant Ecotec Pro 28 boiler, installed from new prior to me moving into my new home 12 months ago.

Suddenly, over the last week the heating has suddenly stopped working. Hot water is fine, but no heating.

This seems really strange. I have totally drained down the system thinking it may have been a blockage but it wasn’t and I am totally clueless.

Now, if I go into the diagnostic menu, d70, it will allow me to change the settings to constant heating - turns off the hot water mind but the heating does work. It seems though that under this (fudge) the thermo doesn’t work either on the boiler or the wall and the heating is set to full blast!

Has anyone ever come across this before, back to factory settings i.e. d70 set at zero the heating doesn’t kick in at all whether on constant or timed? Someone has said it may be the diverter valve but I’m not sure?

Thanks in advance everyone!

 

[mickyg]

what controls do you have? do you have a multimeter? can you check for 240v on terminal no.4 on a heating demand?

also set D96 to 1 this will reset to factory settings.

 

[jacknicmeg]

Yeah, have done the d96 but no good, still dont kick in. Constant green light as if all is OK but nothing but cold rads.

Tell me again re the multimeter, whereabouts as i drop the panel. Have you got an instant msgr program? do you wanna pm me with your addy if you have and you fancy a chat?

 

[Softus]

Have you got an instant msgr program? do you wanna pm me with your addy if you have and you fancy a chat?

Cilla! Get yer 'at, chook.

 

[jacknicmeg]

LOL, not like that at all, sometimes its just easier!

 

[gas4you]

Forget the 'd' numbers for now.

When you think there is a demand for heating press the 'i' button and see what 's' code is showing.

This will tell you if the boiler thinks it is receiving a call for heat or not.

 

[jacknicmeg]

Hi,

Have tried this but no error code comes up, just changes to the BAR pressure and the actual temp. Driving me crazy now.

Again last night had to blag the boiler via the d70 setting but can’t keep doing this long term.

Seems strange, green light on the boiler, could it be the diverter valve and if so, would it be a motor change or the whole unit? Could it be anything else, have you come via this before?

Thanks.

 

[Agile]

If it was the diverter valve the boiler woul fire up every 15 minutes to keep the plate heat exchanger warm which you say its not doing and it would show a temperature of 75°.

In any case you have proved the diverter valve is working because you can force the boiler into CH mode.

If you want to diagnose the fault then you have to test with a multimeter as stated above. It sounds as if you have no CH demand!

I am surprised you dont get a status code when you press the "i" button.

Tony

 

[jacknicmeg]

Interesting... I'll try it.

Is there a particular way the I button should be pressed? Am I switching off then on with the finger held on it?

The diverter valve does move, it will centralise and stuff so it might even not be that?

So, if I put the CH on constant, that’s a demand for heating right? Nothing when the I button is pressed or even held and pressed?

 

[Agile]

A demand for CH occurs when the 230v voltage is applied to terminal 4.

NOTHING else!

To achieve the voltage at T4 the timeclock/programmer and roon stat all have to be set correctly and working.

Its not worth us discussing this any further until you have checked T4.

Whilst you can do some checks in the boiler's software, at some point you have to do real electrical tests with a meter.

If a single press of the "i" does not engage the status then there is a possibility that the PCB is faulty and if its faulty that may be why its not responding to a demand at T4. So yet again we are back to the T4 check.

Tony

 

[The831Bunny]

Hi

Please refer to gas4u (Daves) reply above. Turn up your room thermostat to maximum, turn on your time clock to constant heating. Press the i button once. You will now have a Status code on the display.

S.30 there is NO demand from your external controls. S.4 Heating demand/Boiler flame established and on.

Ignore any codes that show as S.97 S.98 S.1 S.2 and S.3 as these are codes that will appear before S.4.

Wait for up to 1 minute for the S.4 to appear depending on your eternal controls (wireless etc). On that note have you checked your batteries if you have a wireless room thermostat

Cheers Bunny[/u]

 

[The831Bunny]

My next step Tony!

Regards Bunny

 

[jacknicmeg]

Everyone,

Have got the multi-meter out and tested terminal 4, there is definitely 240v there.

Have pressed the "i" button and the fault is sticking with S10 which, according to the manual is "Hot Water Demand".

The heating is now on constant, stat turned up full (its not wireless) and the green light on the boiler is displayed however plenty of hot water but no heating.

The boiler however, around every 5 minutes does strike for about 5 seconds then goes off to normal.

Any ideas?

*scratches head!

 

[The831Bunny]

Turn off your mains cold water (either at the cold isolation valve on the boiler or perhaps easier at the main stopcock).

If after a minute or so the boiler swaps to heating (S.4) then you have either a) a dripping hot tap or b) a leak on your dhw pipework downstream from the boiler.

You can check this by putting your hand on the second pipe in from the left under the boiler and feeling if its hot. If it is (and I'm sure it will be) check d.36. This will show you how much water in litres per minute are flowing through the boiler.

Hope its a dripping tap....

Bunny

 

[jacknicmeg]

Does the hot tap need to be open? And the boiler left on i guess.