Vaillant ecoTec 418+ Taking Longer to Reach Desired Temp

[Dunbar]

Have noticed over the last view days the process has slowed considerably. Normally, the boiler fires up soon after the room stat clicks in and it gets up to desired temp within a few minutes. Have noticed the boiler is much quieter when it does ignite (approx 10 mins after being switched on) and today took 40 mins to reach 65 degs. The only thing I've tried it a reset, but still the same. Any advice would be appreciated.

 

[Last Plumber]

Have noticed over the last view days the process has slowed considerably. Normally, the boiler fires up soon after the room stat clicks in and it gets up to desired temp within a few minutes. Have noticed the boiler is much quieter when it does ignite (approx 10 mins after being switched on) and today took 40 mins to reach 65 degs. The only thing I've tried it a reset, but still the same. Any advice would be appreciated.

What is the status code on the facia display when it is running slow?

 

[Dunbar]

What is the status code on the facia display when it is running slow?

It's s04

 

[Last Plumber]

That's normal so is it doing anything else such as heating the hot water at the same time?
Try heating only on the programmer to see how it performs on that.

 

[Dunbar]

That's normal so is it doing anything else such as heating the hot water at the same time?
Try heating only on the programmer to see how it performs on that.

Thanks for your reply. I ran it on 'chimney sweep' mode and it seemed much livelier. It seems on normal mode it's running on low power with a smaller flame and taking longer to heat the rads. Normally after a minute or so of coming on I can hear it clearly, now it's quiet from the word go. Only serviced a couple of weeks ago. I also checked it when heating rads only and it's the same.

 

[Scott_D]

Has it been range rated? Check the bench mark or D codes.

 

[Last Plumber]

As above, if it is running s04 it thinks all's well so check the D000 to see it is in auto. Maybe the person who serviced it altered it? Is it a small house.

 

[Dunbar]

Think that was it. I got the person round who serviced it yesterday. He was here for 90 mins and part of that time he was speaking to someone at Vaillant, but didn't charge me. He mentioned three things, the condensate siphon, the ignition electrode and the heat exchanger. I think he checked the first two of those and then spend a log time checking the codes. Whatever he did, boiler now firing up and reaching desired temperature much quicker.

Thanks for the comments.

 

[Dunbar]

Been working OK for a week or two, now noticed that it's taking longer again to fire up properly. When its due to come on, the flame starts off at it's lowest, and temp creeps up slowly. Then after around five minutes the flame gets up to around half way and temp moves up more quickly. I spoke to Vaillant who couldn't help much, apart from telling me to up the flow temp to 75degs from 70 degs.

Might be bothering too much about this, as water and rads heat up fine, and if the expert advice is that what is happening is in the normal range, I'll stop. Just that before the boiler was serviced, it fired up as soon as it was due to come on, so still wonderings if settings were changed and if they need adjustment.

Re comment from Last Plumber above. How do I access those settings (D000). Cheers.

Thanks again in advance for advice.

 

[Scott_D]

Sounds normal.
Starts in minimum then ramps up then modulates down

 

[Dunbar]

Thanks Scott. Before service, the low monitoring state was no more than a minute or so, and now around 5 mins, but if you reckon that is within normal range I'll stop worrying.

 

[John.g]

Normally, it might take 30/40 minutes to get up to temperature only in the mornings when the whole system contents must be brought up to temperature.
I wouldn't think 5 minutes monitoring is normal, someone here monitored his which appeared to fire up at ~ 13.9kw then fell very rapidly to (the equivalent) 9.6kw for exactly 60 secs and then ramped up or down until the desired boiler flow set point temperature was reached.
If you have zoned rads, put one zone only on, say 3 or 4 rads and monitor the temperature rise, if the boiler is being held on this 9.6kw setting for 5 minutes the temperature should still rise fairly quickly and may even cut out on over temperature.

 

[Dunbar]

OK, thanks for the input.

 

[Dunbar]

Just to close this off. I still wasn't happy with the boiler performance, so called Vaillant in with the risk of paying £98 if the engineer said it wasn't a job under my extended warranty. Initially he said it was operating within the acceptable range, and changes during the seasons. However I said it hadn't been working like that for the four years since installation, so he put a new pcb in.

Boiler now roaring again with flame around three quarters up symbol, where as before it only got just below half way, and now no more waiting for over five minutes before it limped into life.