Danfoss FP715 flashing ON

[NornIron]

Hello everyone, I have a Danfoss FP715 used in conjunction with my central heating however a second ON indicator is now flashing on and off on the LCD screen, any ideas what this is or what it indicates?

Thanks in advance

 

[JohnD]

Have you got a hot water cylinder?

How big is your house?

Is it rented?

A photo would be useful, showing this indicator.

Have you seen this?

 

[RandomGrinch]

Manual attached, if it helps...

 

[NornIron]

Have you got a hot water cylinder?

How big is your house?

Is it rented?

A photo would be useful, showing this indicator.

Have you seen this?

Hello John, thanks for your quick reply. We do have a water heater, house is two story and not rented.

Please find a photo, sorry it is hard to capture as it flashes on and off. I have noticed this is a small battery symbol after taking the photo, this is flashing to the right of where the rectangle would usually be to indicate ON.

Thanks also for the video.

 

[NornIron]

Manual attached, if it helps...

Many thanks RandomGrinch

 

[JohnD]

Looks like the standby battery is running down, or it is not receiving mains power. I do not have a Danfoss here to try out. The manual should help

 

[DP]

Looks like the standby battery is running down, or it is not receiving mains power. I do not have a Danfoss here to try out. The manual should help

I suspect power is switched off
FP715 us mains operated.
If the red light is flashing, time to replace the programmer as power supply might be operating poorly.

 

[RandomGrinch]

As @JohnD says above, check for mains power.
If there is mains power, the onboard backup battery may be dead, or dying. It can be something you can live with - the only issue would be, your settings would be lost in the event of a power cut.
The internal battery could be replaced if you are handy with a soldering iron!

Otherwise, it may be...

time to replace the programmer

 

[ianmcd]

The setting storage battery has failed, new programmer time

 

[JohnD]

If you are handy with a soldering iron and can be bothered, you can get a Varta green lithium replacement battery off ebay very cheaply. They are charged by the timer. I think it was Bernard who put me on to them. Some are available with wire pigtails which are easier if the original was designed to be difficult to change.

Edit
Here we are. Varta Mempac (yours may be a different size as it is not the same device). I thought it was Lithium, but NiMH
IIRC they are cheaper on Ebay as my RS account has expired now.

Danfoss TP75M Programmable Room Stat (battery)

I recently fitted one of these, I got it cheap as NOS. It has a rechargable battery inside, as mine has been on the shelf for about 6 years the battery appears to have deteriorated and will not hold its charge for long. Does anyone know how to change it? TIA

www.diynot.com

 

[NornIron]

Hello again everyone, well due to the FP715 giving issues I have ordered another "new old stock" one and await it's arrival. I did get the heating going again with the current one however another issue is arising when it is running. There is a 3A fused spur in the hot press where the motorised valves are, however this keeps blowing. The heating ran for a number of minutes and I could feel great starting in the radiators then all went off, FP715 had a blank screen. If I change the 3A fuse I can get everything powered up again, start the heating then fuse blows again. Any ideas what could cause this? Could the FP715 be completely done? The second 3A fuse I fitted blue and also tripped a Hager MB106A circuit breaker as well.

All had been running fine until the battery light came on the FP715, so I am only presuming it is it causing the issues.

Any insight or further thoughts would be greatly welcomed.

Thanks

 

[RandomGrinch]

All had been running fine until the battery light came on the FP715, so I am only presuming it is it causing the issues.

This all sounds backwards!

As we mentioned earlier, one of the reasons for the battery display to flash, would be if the FP715 wasn't getting any power.
The fuse had possibly already blown, when you noticed the display start to flash.

To me, the failure mechanisms for the electronics within the FP715 don't add up with your description of the faults.

I may be wrong, but I think your problem may have been elsewhere all along - items such as pumps and valves are good things start checking.