Boiler elan 2 problem

18 Jun 2017
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United Kingdom
Hi All,
I am Ludo a new member. I have an elan boiler 2 with a new contrôler FP715- (Si Electronic Programmer ).
Recently, when the water heater program start, it doesn't heat the water tank but heat only heaters and excessively although the heaters program is not on.
Any idea ? Do you think the expansion vassal could be the problem? Thanks.
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Ahhhh I remember fitting my first Elan2 in 1988

Your problem is likely to be in the central heating controls. Check the wiring and check that the mid position valve is free to move.
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nothing whatsoever to do with the expansion vessel (if you even have one) most likely that your system is open vented , but even if it is sealed it has nothing to do with the expansion vessel, you have an external control fault, as already advised look at the mid position control valve
Many posters could learn from you Ludovic, being polite will always get you the correct advice , if you can post a photo of your Mid position valve I will tell you how to test and repair or replace it as is necessary
Thanks again
I'll try to post pictures if I can.
Ok, 2 first pictures are for the curent controller.
The 3 last pictures were for the old (replaced) controller without any diagram available .
Also attached the diagram picture from the elan2 boiler itself.


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Thank You Ludovic can you post a pic of the mid position valve please so I can see which type you have , should be near your pump , possibly in the same cupboard as your Hot water Cylinder ?
I guessed the pictures attached will be in.
The old controller was a sunvic so as I suppose the valve and a junction box I noticed on top.
I didn't open the junction box as it's dark underneath.
At that area I have the motor, the valve, the expansion vessel.
The water tank is upstairs and have it thermostat attached to it.
I took out the sunvic (valve?) and took it picture alone with it diagram.


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OK what the actuator head that you have removed does when working correctly, the pipe at the bottom of the tee into the valve is the feed , when HW is called for the valve actuator turns the valve for HW same with CH when both are calling for heat at the same time then it sits in mid position, you need to watch what happens when you call for heat when in HW or CH mode if it does not move then you probably need a new actuator, you can manually set it to give you HW while you get a new one
Good morning Ian
I would do it and observe what's happening.
1 picture was missing in my post yesterday.
The curent controller which seems to be working before this start happening.


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that is you Programmer, the valve will have 3 pipes and a cable and usually a silver box or a white box on top
Hi there,
Ian I did what you recommand and manually,it's all working ok.
I also order a new sunvic actuator head via eBay who have the same item as the current one for £64.
I will receive it tomorrow and install it.
I will keep you updated.

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