New Bosch Worcester Greenstar 37 CDi Boiler EA Fault code

Hi Folks,

Have just had a new central heating system installed comprising :-
New combi boiler - Bosch Worcester 37 CDi,
new radiators,
new TRVs
new pipework (15mm copper replacing 8mm microbore).

The property is unoccupied whilst we refurbish it, although we're there most evenings and weekends.

Existing pipework was retained for cold water supply to boiler & domestic hot water. System was supplied and installed by a GasSafe plumber from an approved Bosch agent (a long established local business).

System pressure has remained constant for about 2 weeks - the system was bled and re-pressurised the day after installation / commissioning.

System works fine when the central heating is on (ie at times when the central heating clock is set to activate the central heating).

However if we run the hot water tap outwith these times (ie CH off) the water runs cold. The "Burner on indicator light" illuminates momentarily then goes out (for about 45 secs?) after this happens four times the boiler displays fault code "EA" ("Flame not detected") and the fault and mains power (blue) lights flash.

Reseting the boiler clears the error but the error returns if we run the hotwater. If we "Advance" the central heating clock (ie turn CH on) then boiler goes through a slow start warm-up (-!!- and XX (temp) alternate) for about 15 minutes (Bosch manual says this is to fill the condensate trap?). Then central heating and hotwater then both work OK.

Supplier has sent the plumber out a number of times and reports that the pressures and tempeartures are all ok and it's an air lock caused by the fact it's a a new system and the chemicals they put in. I think it's a boiler / install fault and the chemicals should only be in the CH system (would turning on central heating clear an air lock in DHW supply?).

This has been going on for 2 weeks and we haven't accepted the system (or received their bill) yet but we are getting exasperated and feel like taking the whole lot out and dropping it on their doorstep.

Can anyone advise what we should do eg persevere with the supplier or try contacting Bosch direct. Finally does anyone have any ideas as to what could be causing the problem?

THANKS

 

phone bosch direct ,good boiler just unlucky,bosch will sort it

 

A air lock would A: be very unlikely on a sealed system B: allow your heating to work and not your hot water.

i'd be asking your installer to look at working pressure and air/gas mix although this should have been done during the comissioning......

If you're getting an EA fault on HW only, I'd be suprised if its a boiler fault, more likely a installation fault such as under sized gas pipe or not set up properly.

What diameter is the gas supply and how far from the meter? how many bends? 37Kw is a fair sized combi but a good un, i have one

 

Yes I vote for undersized gas pipe, partially closed ECV, or duff regulator on the meter.

Your installer may have checked for these issues by measuring the working pressure at the boiler when it is in engineer or HW mode. If not, that would be where to start.

NB: if they haven't shown any desire to call out the manufacturer themselves you can bet the gas pipe is under par.

 

This says to me it may be wired wrongly as you should only get
-||- after the power supply has been reinstated after isolation.

 

I was just about to say the same thing.

It sounds as if he has NOT connected a permanent live correctly and the programmer is interupting the permanent live when it operates so that when it is restored the boiler thinks its a new installation and goes through the fill the condensate trap procedure of running for 20 min at minimum power.

If you call Bosch they may charge if its an installation error as we suspect !

Ask the installing firm to send someone more competent to check the way its been wired. If you are handy with electronics you may even be able to do that yourself.

Tony

 

I assume that when you say it works fine in CH mode, then every so often you hear the condensate trap emptying - it fires up for a few seconds and then switches off again. In addition to what's already been suggested, check there are no blockages in the drain pipe from the boiler to the condensate trap. I had that last year with an EA code and numerous parts were replaced before the fault was found. If the pipe to the condensate trap is blocked, or the trap is broken and cant empty, you get a backlog of waste gas vapour that cant escape, this causes a lockout. Does sound like installation error though.

 

Folks,

Many thanks the supervisor is going out to have a look tomorrow (Tuesday) so hopefully he'll spot something.

The gas supply is 22mm, the pipe run is about 12 metres from meter to boiler and I'd guess there are about 6 (give or take) 90 bends along the route.

From your description I think the condensate trap is working but as we're not there much it's difficult to tell. When I said it works fine I meant that the central heating works (ie rads get hot) and we get hot water too (sorry).

Thanks again.

 

I'd guess that your boiler is under gassed. Any other gas appliances?

 

That pipework looks a bit borderline for your boiler.

 

copycat

 

There seem to be two faults.

The apparent lack of ignition seems to me to be more likely to be as a result of a sticking regulator than an undersized gas pipe.

Its easy for a competent gas engineer to test for both though.

Tony

 

Sorry for the delay in updating everyone...

The supervisor eventually came out, and "fixed" the boiler (I was told it the pressure hadn't been set correctly at the boiler, and my partner was told it was water in the burner). Anyway when we tried running some hot water it ... FAILED with error EA .

The Bosch engineer came out, unfortunately not on the day they originally arranged and as we couldn't get any more time off the plumber had to let him in.

Got a message saying it was a "faulty gas meter regulator and get BG out to replace the meter". Supply pressure was dropping to 3milli bars (?) when the hot water was turned on.

Transco came out and replaced the regulator(?) at the meter and the system now works.

Call me cycnical (amongst other things) but since the Transco guy replaced the meter part without checking anything (and we didn't get the opportunity to try the boiler before he arrived) isn't it a of a coincidence
that the boiler started working after the Bosch engineer visited and and that it took more than 7 visits to spot the "faulty" gas meter?

Now we wait with bated breath for the bill...

THANKS to all for their assistance.

 

Thats what I said on the 26th April without even being within 300 miles of the boiler!

 

Hi Tony,

I'll gladly buy you a beer (or 5 ) rather than pay their bill!!

We're (my good lady wife and I ) still debating the "long established local firm with a good reputation" question not to mention how much we should ask off their bill for the hassle (and the water stain in the newly painted ceiling).

THANKS again!