Vaillant Eco+ switching on and off

[rowedout]

Hello - we have had a vaillant system for a couple of years and heats everything up great, a really good system, but....
is it normal for it to keep switching on for about 3 mins then clicking off for a few seconds and repeating this when the systems dials are at max? We have a Honeywell mobile thermostat and set on Manual to reach 23.5C but it never reaches that before turning off?
Should it keep switching on/off
Many thanks for any advice
Adam

 

[simond]

Your radiators in the room containing the Honeywell stat are incapable of getting the room to 22.5C.

Reasons could be;
1. rads aren't big enough
2. You have thermostatic valves in the room containg the Honeywell stat
3. Poor flow round heating system to the rads in the room containing the room stat causing low water temp in the rads
4. You've left the window open

 

[Agile]

That would not be normal.

But if the boiler has not been set up properly then it may be doing what it is set up to do.

Was it professionally installed? Is the Benchmark Certificate completed ?

Did you have it serviced at the end of the first year to preserve the warrantee?

Tony

 

[rowedout]

Many thanks Tony and Simon.
Simon - good points that we will try to resolve
Tony - we didn't get the boiler serviced as we should of (new baby takes up most of our time!), it was fitted by a pro. The actual boiler clicking on/off is next to our bedroom which is the problem as we had the radiators replaced with better, quieter ones and they cause no probs.
Best bet I think is to get it serviced and see if they can recommend anything

thanks very much for taking the time
Adam

 

[mickyg]

how many radiators have you got?

 

[Agile]

If you want to fiddle then you could set d0 to the lowest possible figure, perhaps about 8 kW rather than the maximum the installer probably left it set at.

That might enable it to stay on for longer.

What temperature does the display go up to?

Perhaps Mick has an idea but at the moment I cannot think of why it would go off for just a few seconds with typical boiler settings.

Tony

 

[Melvin476]

Dear Friends,

2 weeks ago, I had a similar problem with the new Vaillant Ecotec 418, just installed by a local GasSafe fitter. He seemed to have no idea and said that there could be a significant water leak into the concrete floors.

So I got the Vaillant Engineer to have the 2nd opinion. It was a free inspection service by the boiler manufacturer.

He spotted the mistake immediately and got it sorted out by the fitter on the same day. The frequent on-and-off stopped immediately and the boiler has been working normal since then.

The fitter did not refer to the boiler manual and got the pipe connection wrong. The Cold Feed pipe was connected to the Return pipe from the radiators. Once it was re-routed to the forward flow pipe towards the Radiators as shown in the Manual diagram.

Do have a look at your pipe work? It may solve your problem.

 

[MrV]

Hi,

i'm guessing that what it is you are hearing turn off and back on when you say the boiler runs, is the Pump.
The pump has a minimum 2 min overrun after it has reached temperature and the flame has gone out. It will then carry out a quick self check and if external demand still exists, it will then subsequently fire up again. it will continue to do this until the external demand finishes.
This is nothing wrong with the boiler but it is highlighting an issue to you.
The most likely issue is that the Power output of the boiler is greater than the heat requirement of the central heating and therefore the boiler is reaching temperature before the system is. This usually comes down to poor setup.
Though I would suggest to you that you get a decent heating engineer or Vaillant themselves to come and make some tweaks and checks to it rather than playing around with the boiler yourself.

 

[Agile]

The OP has said that it goes off for just "a few seconds"!

Thats not going to be any normal boiler delay.

Tony