What's wrong with my Vaillant Ecotec Plus boiler?

[MaryJane7]

When my central heating (but not hot water) is turned on there is a brief ignition of approximately 30 seconds before the ignition stops and an error message of S.53 appears, that is (according to the manual), 'appliance is within the waiting period of the operation block function due to water shortage (VL - RL spread too big)'. The boiler can remain in this state for up to 30 minutes before it successfully ignites and appears to work.

This problem occurs whether (a) the central heating has been off for some hours, typically overnight, or (b) when the central heating has been off for some minutes, typically when the living room has reached the temperature dictated by the room thermostat and the room temperature has then dropped and so the boiler tries to get going again.

The problem does not occur when the hot water is turned on immediately prior to the central heating being turned on.

So far I've had (a) new pump fitted and (b) new heat exchanger fitted. But problem continues.

Any help/ advice gratefully received.

 

[Deleted member 105431]

I would check the ntc's are the correct way round on the flow and returns in the boiler (white boot spades go to rear ntc, black to front), check it has been range rated using d0, check system for blockage/valve closed, check "canoe" filter isn't blocked.

It appears you have a circulation issue causing the flow and return differential to exceed 20 deg c.

 

[gas4you]

How old is the boiler?

What did it replace?

Who has replaced the pump and HE?

 

[MaryJane7]

Thanks to gas4 you and Dangermouse46 for looking at my problem. Much appreciated.

These are the answers to your queries:

1. the new boiler was installed by a qualified CORGI plumber in February 2008, but I didn't use the central heating function alone until the end of November 2008 (before then I only used the hot water system alone, or had a one hour session with both hot water and central heating system working together)

2. the old boiler (Ideal Excel 40 Balanced Flue Gas Boiler) worked fine but was 20 years old and, what with all the publicity about energy saving, I (foolishly!) thought I'd better replace it before it went wrong

3. when I first realised that there was a problem I notified the installer and he came out and replaced the pump

4. when this didn't work he told me to contact Valliant and their engineer came out and fitted a new HE (after, on Valliant instructions, the installer had drained and rinsed the system)

5. before leaving, the Vaillant engineer said that if the new HE didn't solve the problem then it wasn't a boiler problem and I needed to get the installer to sort it out; but when I phoned the plumber he said that its a sensor problem (that is, a Valliant problem) and, though he said he'd come out to have a look, I've heard no more

6. I'm afraid that I didn't understand the queries raised re canoe filters etc, sorry.

What do you think?

 

[Agile]

This is a common problem on your boiler and there does not seem to be a simple solution.

D Mouse is a service engineer for Vaillant and ideally qualified to give the best advice but he does need you or your installer ( Mike? ) to do the preliminary checks first.

I am watching with interest and please do keep us updated on the progress.

Did the installer power flush the system with a noisy pump and lots of pipes for several hours?

Is the heating system started with 22 mm pipes from the boiler?

Tony

 

[MaryJane7]

Your initial comment sounds a bit worrying, Tony!

Its in the quote that the installer power flushed the system before installing the new boiler in February (I wasn't here unfortunately), and then he just drained and rinsed the system in December when the Vaillant engineer asked him to.

Have looked at the pipes and yes they are 22mm from the boiler.

Hope this helps

 

[mickyg]

what model is it??

 

[Deleted member 105431]

what model is it??

If it's a 400 then it needs range rating before you do anything else, if it's an 800 see my previous post. Its worth checking the ntcs are well positioned on a straight bit of pipe.

 

[mario500]

Surely this appliance will still be under manufacturers warranty?????






Al

 

[gas4you]

Describe the 'Vaillant' engineer along with his accent etc, who came out and said this?

There is only one Vaillant agent covering this area who really knows what he is talking about. If it wasn't him I would take those comments with a pinch of salt

A proper engineer wouldn't replace the HE without due cause.

We are talking about the main HE here are we?

 

[mehran]

out of interest, how does the boiler come to decision that it is out of range?

does it fire up gives it a minute then checks to see if the flow and return is with in 20 degrees of each other? i don't know anything about this boiler and was just wondering.

 

[jackthom]

MaryJane7 you can easily reduce the boilers maximum heat output yourself and this will make the S53 code less likely to appear.

On the front panel press both the "i" and the "+" buttons together.
The boiler should display d0

Now press "i" and a value (probably twenty something) will appear.
Make a note of this so you can go back to this value if required later.

Press the "-" button to reduce this value (try around 18 and see how it goes). The new value will be flashing.

Finally hold the "i" button for several seconds until the display returns to d0 and the new value will be stored.

The boiler will now be limited to that maximum number of kilowatts.

 

[Agile]

Its in the quote that the installer power flushed the system before installing the new boiler in February (I wasn't here unfortunately), and then he just drained and rinsed the system in December when the Vaillant engineer asked him to.

If the Vaillant engineer was not happy with the water quality then it sounds most unlikely that the system had been power flushed!

I am having my doubts about him! Probably not Mike then!

Tony

 

[gas4you]

We haven't a Vaillant engineer called 'Mike' covering this area Tony

 

[Agile]

No, I dont mean the Vaillant engineer.

There is someone, perhaps not called Mike, who installed a boiler and particularly solar systems in Norwich for someone I know who lives there.

Tony