Pulsacoil III - Red light flashing 7 times/sec, buzzing noise coming from circuit board

[sbirtwistle]

Hi,

Just moved into a flat with one of these, and so far not having a great experience with it! Found this website and have done very basic diagnostics, could you please suggest what I should do next?

* We have a thermostatic shower that was cold, but bathroom sink and kitchen mixer tap are hot. I think the problem is that mains cold pressure is higher than hot water from the tap having dismantled the shower and found nothing wrong.
* Hot water supply is generally good providing the heater has run recently. By the evening water coming out of the taps is cold (shower is permanently cold).
* Tank on top was not as full as your site suggested, so I topped it up. We were getting hot water prior to this though??
* Took cover off circuit board and red LED is flashing many times a second
* I have never heard the pump fire up while the hot taps are on - suspicious it might be busted

Could you help me trace the fault further?

Thank you!

Simon

[mike]

Well if your shower is cold.
And the other hot taps are hot.
Then it must be the thermostatic shower which is faulty.
Run the shower and when it goes cold feel the left hand side of the shower.
If you can that is!
If hot then water is there.
With ref to the flashing lights etc, Look in the manual and compare from there.
Mike

[sbirtwistle]

It might be the shower - but if I part close the cold water stopcock then I can have a nice hot shower (this is why I suspect pressure difference).

As I don't have economy 7 electric I've set the timer such that the main heater comes on around 5pm, and goes off around 11pm. I never use the boost, just turn on the main feed.

At 9pm there's not enough hot water to fill a bath.

I read your website which says 7 flashes a second is pumped return thermistor failure. Would my experience be explained by that, or is there something else going on as well?

If it helps, I live in London, so it's a hard water area.

Thanks for your help!

[mike]

If you turn the stop cock down.
Then it is;
Slower the water hotter the flow !
Checked the stat.
As set for correct temperature.
Also read the manual as in commissioning the unit.
This will lead you through some basic checks.
Also it could be the PHE scaled up.
Mike

[sunny.sahdev]

I agree with Mike, do those first but also check the pump out, I came across this problem where the pump resistance was very high above 250 ohms and the same problem occurred. Also just make sure you are doing the basics right and your system is reaching its peak temperature. Request this free guide which may help you - Pulsacoil 3 Repair.

If you are still not having any joy, give us a call and we can confirm a few things with you.

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