Baxi 624 system boiler

[DuncanM]

Just installed this and Runs like a dream when going, but when it has been off and cooled down it keeps coming up error code 109 pre circulation fault. Thought maybe air in system and after a few false starts fired up and away it went. Job done, home. Call the next day about the same error code 109 again. Went around and after 2 goes it started again and stayed on all day. Then this am again 109. Going to fit an AAV on return see if that helps.
Any advice greatly appreciated. Duncan.
[automerge]1579602663[/automerge]
Phoned Baxi for a warranty claim.

 

[DuncanM]

Faulty pump. Fitted under warranty. Jobs a good un
[automerge]1579873236[/automerge]
Job not a good un. Phoned back today same bloody fault. Mostly error code 109 pre circulation fault and then error code 125 primary circulation on occasion too. Back replaced pump head and it seemed to be bang on. Then this am, back to the same fault codes. Pulling my hair, what I have left, out. Faulty wav on pump causing air lock?? Any ideas?
[automerge]1579873308[/automerge]
Job not a good un. Phoned back today same bloody fault. Mostly error code 109 pre circulation fault and then error code 125 primary circulation on occasion too. Baxi replaced pump head and it seemed to be bang on. Then this am, back to the same fault codes. Pulling my hair, what I have left, out. Faulty wav on pump causing air lock?? Any ideas?

 

[Scott_D]

What do you think of the 600-800?

 

[DuncanM]

Baxi back out. New temp sensor x2 and a control board. Here is hoping.

 

[Christopher buzzard]

Has it worked? Any call backs?

 

[DuncanM]

Not worked. I have been told now there could be a gauze on the return of the heating that may be blocked, if it is or is not going to power flush system Gonna have to check that, weird thing is circulation seems fine when it does go. Don't get any kettling or anything just kind of fades when it starts to ramp up after about or it goes then faults later. Baxi have been great, so far. If the error codes were not saying circulation I would be thinking flame rectification.

 

[Christopher buzzard]

The duo tec has that gauze filter On the return. Never realised till technical told me. Check them all the time when servicing now. Doesn’t take much to block them.

 

[DuncanM]

The duo tec has that gauze filter On the return. Never realised till technical told me. Check them all the time when servicing now. Doesn’t take much to block them.

Where is it? S it in the boiler connection or in valve? Thanks..

 

[Christopher buzzard]

Switch the black return valve off under the boiler and there’s a nut to undo. On the Combi is where the filling loop connects to usually.

 

[DuncanM]

This is a system boiler. Just a flow and return. Any idea?

 

[Christopher buzzard]

Is this the jig which the boiler hangs on?

 

[DuncanM]

Found it. Had them both off. No gauze. Got the power flush on it now. Hopefully this does it. Thank you for your help!!
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Still got error code 109 after a power flush. Bypassed boiler for fear of blocking it. Cleaned out the entire thing, not an excesses amount came out and i used an SDS gun with an agitator thing on the end of it to rattle the radiators. Got code 109 again. Closed flow service valve, blasted the pressure up to 2.6ish and opened the drain on flow valve then kept filling loop open, hoping to move any air or debris. Tried again and it fired and stayed on. It has done this every time Baxi visited too, then next day it's back to 109 again. Will see what tomorrow brings....

 

[DuncanM]

More error code 109. Now been advised to fit a auto air vent to return pipework near boiler as they are saying air is air locking it. Going to do that. Where does it go from here though if that does work?
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Just had a thought. Should I not fit an AAV after on the positive side of the pump in case it draws air in?

 

[Christopher buzzard]

Have you got a pic of the installation?

 

[DuncanM]

No, sorry. Not much to see. In a pic of it. Boiler tails that came with come out of bottom into a 90 to go off to the right about 300mm on flow then another 90 down about 1m-1.5m behind tiling over a boxing in to another 90 then straight to ch8 and HW circuit. HW goes up to attic where cylinder is (bungalow) Ch around ground floor. 2 port defo open as when it does fire there is plenty of heat around house

 

[EvilDrPorkChop]

Sounds like they're clutching at straws. I'd fit my Auto Airvent at the highest point, so on the flow to the HW circuit in the loft before the MV, assuming the HW MV is in the loft and that it's a 2 port.

 

[DuncanM]

There is a danfoss valve on pipework near cylinder that opens and closes like a TRV near the cylinder.

 

[EvilDrPorkChop]

There is a danfoss valve on pipework near cylinder that opens and closes like a TRV near the cylinder.

So what's your HW control? As that's what they used to use on Gravity years ago...

You must have a MV and a Cylinder stat?

 

[DuncanM]

There is nothing other the that valve, initially I did not see it and assumed everything was ok as no reports of a problem from customer.. silly me. This job has kept throwing things up at me. It was late on a Friday and merchant had orderd wrong room stat and programmer. I just hooked it on to old stat and commissioned it. During commissioning noticed that HW had no control for itself. Thought maybe programmer was wasted. Got a new programmer and temp stat and when I went to wire it up there was nothing to control hot water at all. Told her that she needed to get this done and I would plumb it in for free if she paid materials and a spark. Was going to get BES ones at 26 quid and a tank stat, she does not agree to this work and I have noted it on commissioning sheet that it needs done and wired up by the spark.

 

[EvilDrPorkChop]

There is nothing other the that valve, initially I did not see it and assumed everything was ok as no reports of a problem from customer.. silly me. This job has kept throwing things up at me. It was late on a Friday and merchant had orderd wrong room stat and programmer. I just hooked it on to old stat and commissioned it. During commissioning noticed that HW had no control for itself. Thought maybe programmer was wasted. Got a new programmer and temp stat and when I went to wire it up there was nothing to control hot water at all. Told her that she needed to get this done and I would plumb it in for free if she paid materials and a spark. Was going to get BES ones at 26 quid and a tank stat, she does not agree to this work and I have noted it on commissioning sheet that it needs done and wired up by the spark.

Isn't this what your issue is though? CH shut down, HW still going. Has nothing to stop it, boiler overheats and locks out? Only happens at night cause it's the last thing on....

TBH i'm surprised Baxi hasn't picked up on that. Certainly needs rectifying, can't be left like that even if it is or isn't causing the issue.

 

[DuncanM]

I told Baxi the situation with the controls. They never said anything. I am happy to do it just it is something I have not budgeted for it and the customer is not wanting to pay. I would happily fit them but the spark still needs paid.
[automerge]1580329003[/automerge]
It's not overheating. The thing ignites then goes out with fault code 109. Happens when cold. I am just gonna have to pay the spark just to get it up to standard. Wish I had been under the floor before stating, but you expect everything to be in place. Was a bit like oh no! When I saw the set up.