Vaillant Boiler - expert advice needed!!

Joined
30 Jan 2005
Messages
21
Reaction score
0
Country
United Kingdom
Here's the thing - with the onset of summer, I switched my boiler off to save energy or rather to save money. This weekend I have got visitors so thought I had better not look like such a skinflint and I should let them have hot water!!

Anyway, when I switched the boiler on - nothing. No LCD display or anything. Not even a sound from the boiler at all?

Does anybody have any idea of what could be going on? I could cope with an error code or something but the boiler is just, well dead. I am hoping it is something fairly simple, which will restore the LCD display and spring everything else into action. Oh boiler fairies please let this be so ...... :)
I think the boiler is an Ecomax and it is 5-6 years old.

Thanks for your help!
 
Sponsored Links
Vaillant (and others) have an antiseize function on their boilers. This runs the pump on the boiler for one minute every 24 hours. I suspect, by disabliing this, the pump has seized and blown the 2 amp fuse on the pcb.

You may be able to 'spin' the pump and just replace the fuse. Remove the pump vent screw - the silver screw in the middle - and trun the impeller with a screwdriver. Beware water will come out and do not get the pcb wet.

Good luck and remember don't turn the boiler off again. Just turn down the control knobs.
 
Here's the thing - with the onset of summer, I switched my boiler off to save energy or rather to save money. This weekend I have got visitors so thought I had better not look like such a skinflint and I should let them have hot water!!

Anyway, when I switched the boiler on - nothing. No LCD display or anything. Not even a sound from the boiler at all?

Does anybody have any idea of what could be going on? I could cope with an error code or something but the boiler is just, well dead. I am hoping it is something fairly simple, which will restore the LCD display and spring everything else into action. Oh boiler fairies please let this be so ...... :)
I think the boiler is an Ecomax and it is 5-6 years old.

Thanks for your help!

check to make sure that fuse spur has not been turned off .l
 
Wow thanks everybody! Sorry it's taken so long for me to reply - I've been offline for a while. I have now come to realise that I am going through an "everything breaking at once" phase so I am hoping your advice will work! I will muster up the nerve to have another look at my boiler. I think that once it works again, I will never switch it off again!

I will let you know what happens and hopefully I will get away with fixing it without having to pay somebody else to do it!

Thanks! :)
 
Sponsored Links
You were right, it had blown one of the fuses! First of all I changed it, and the boiler started to fire up but then died again. When I looked it had blown the new fuse. I tried the thing with the pump and took the silver screw out but I couldn't turn the middle with a screwdriver because it was just a square hole. I thought an alan key might work but it was the wrong shape. Is there anything special I could get that would fit the hole so that I can turn the pump?

Thanks again!
 
The shaft end has a screw driver slot with sides at about 45 degrees because they think there is a danger using straight sides.

A 4 mm wide blade pushed firmly inwards usually turns it.

If its really stuck then drain and remove head and see if a hand on the impeller will make it turn.

The FAQ may give you useful information.

Tony
 
Well, I managed to check the impeller and it was surprisingly easy to move about (thanks for the advice about using a screwdriver!). Unfortunately the 2a fuse still blew and then the fuse in the switch for the timer blew too!

I think I am going to have to admit defeat - which I hate doing because I felt really positive this morning!

Just another thing though - is the red wire not meant to be attached to anything? 7 8 9 were free of wires. All the others had wires in them and number 5 was free with a red wire not attached to anything at all. I know I'm clutching at straws but I thought I would just check...... :confused:

Thanks!
 
DO NOT conect anything to 78&9 they are for a German control system.

Connection 5 is an additional neutral connection - not needed.

Unplug the pump from the pcb, replace fuses and turn the boiler on. If the fuses don't blow, you have confirmation that you need a new pump. A grunfos 15/60 head will fit ;)
 
The saga continues........

I unplugged the pump from the pcb and put in a newly bought fuse but it still blew. I plugged the pump back in and put another fuse in and it blew again. I rang Vaillant (my boiler is a Turbomax not an Ecomax as I said originally - Doh!) who told me that they would come out to it for £260 or I could have instant cover for £299. I can't afford that so I made my excuses and put the phone down.

I put yet another fuse in (without touching it this time - I don't know if that made any difference) and switched the boiler on but this time the fuse didn't blow! Hooray! The trouble is, I daren't try switching the hot tap on because I know it will blow again.

Anyway, to continue with the loose red wire saga - any ideas which number it should go in? The timer/thermostat didn't come on when I switched the boiler on so I am guessing that this is what the red wire belongs to - I just don't know which numbered wotsit it should go in. I know it's not 7 8 or 9 because you told me before and I know it's not 5 because you told me that too!

If I end up getting a working boiler without having to fork out £260 it will be a miracle - but I will persevere! :confused:

Thanks again for your help!
 
Have you considered getting a good local independent engineer to diagnose the fault?

Tony
 
I have Tony and I will do but I always think I can fix things myself - until I get fed up and admit defeat!!
 
Now we've got the right boiler, I can give better advice.

Put the boiler in demand (run the hot tap) and turn the power on.

If the fuse blows immediately it's the pump;
If the fuse blows after 20 seconds its the fan:
If the fan runs then the fuse blows it's the gas valve - two types of these.
The honeywell (grey plastic cap) has a diode in the lead and can blow the pcb aswell, the SIT (clear plastic cap) will be the valve.

Try this, hope you've got enough fuses :)
 
But he seems to have said that the fuse blew WITHOUT the pump connected !

He has not disconnected the gas valve cable at the PCB end or even told us which make of gas valve is fitted.

It is fairly rare but sometimes a gas valve solenoid can short to the chassis or have shorted turns which take an over current.

I know people love to talk about fans blowing fuses but it must be nearly 10 years since I last had a fan apparently blowing fuses and that turned out to be an overheated cable shorting to the chassis as it passed the combustion chamber.

Tony
 

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.


Are you a trade or supplier? You can create your listing free at DIYnot Local

 
Sponsored Links
Back
Top