Pulsacoil 2000 -Hot water in the thermal store but cold water from the taps.

Hello

Sometimes my pulsacoil 2000 stops working.

The water in the thermal store is hot but there is no hot water coming from the taps.

So far I've solved the problem by switching off the boyler for a few minutes , when I switch it back on I get hot water, the problem is now happening more often.

Any suggestion on what the problem could be?

PS: The red light is flashing about 2 times per second and occasionally flashes continuously, but it has been like that from day 1 , the boyler is about 7 years old

Thanks
Tony

Hi Tony,

Check if you have voltage at the pump when you request heat at the taps.

If no voltage at the pump you are looking at replacing the DHW sensor.

Kind regards

Gary

MK Group Ltd

Hi Gary thanks for your reply.
This morning it happened again, I woke up with no hot water at all, i wanted to check if there was voltage at the pump as you advised me to do but not sure how to do it.
How do you check voltage at the pump?
Do you mean the read light at the Pump Speed Control? Do I need to check if it flashes normally?
Could you please be a bit more precise, I'm not an expert, I'm just trying to save the call out charge if I can as this boyler has already costed me a fortune in repairs :(((
This evening when I came back home I had hot water as normal, I didn't do anything so when it happens again what do I need to do precisely?
Many thanks for your help.

Tony

Hi Tony,

If you are intermittently getting hot water please check the following:

Check the header tank is topped up with water (the small tank on top).

If your store is hot but no hot water at the taps check to see if the pump is running (you can do this by touch or take the silver screw cap off the pump, a small amount of water will come out, check if the internal screw is turning around).

With a multi meter test when the taps are open if you have 230V at the pump. If not then you are looking at replacing the DHW sensor.


Let me know how you get on.

Kind regards

Gary

Hi Gary,
This morning it happened again, there was hot water in the boyler but cold water at the taps, the header tank is full, I learned this lesson a while ago.
While running water at the hot taps i checked the Pump speed control board and all seemed fine, the red light was flashing twice per second - you said that I can check if the pump is running by touch... but what do I need to touch exactly??
And i don't see any silver screw cap off the pump..... the only silver screw cup i see is the one on the DHW sensor.... but I don't think that's the one you mean.
I touched the Plate heat exchanger and it was stone cold.
I’m thinking of buying a multi meter test but how will I check if I have 230v at the pump??
Sorry Gary I’m not very familiar with all this stuff, could you be a bit more clear ?
Many thanks for your time
Tony

HI Tony,

You will need to purchase a multi meter. once you have one let me know.

Kind regards

Gary

MK Group Limited

Have same prob. Water store full of hot wter but cold at taps. Getting 50volts at pump sometimes ramps up to 110Volts then get a little hot water. when i put supply direct to pump get hot water. Is this a sensor or PCB problem? If so what code do I require for the part and where from?

Hi,

Sensor issue, replace the dhw sensor and phe sensor.

Regards

Gary

One more thing do you know the part numbers?

GT153

Thanks will give it a shot

Soz but one more question. Think one of the sensors is in a wet pocket, Are both sensors the same code GT153 and am I liable to need a new glanding kit to fit the wet pocket sensor

The wet pocket sensor is a PHE return sensor GT149, you won't need a gland kit.

regards

Gary

Thanks for your help will give it a go! :-)

Hi Gary

I will swap the sensors as well, but I’m a bit confused on what to order.

The white sensor is the DHW sensor ( wet pocket ) and the reference is GT153
The gray sensor is the PHE sensor ( dry pocket ) and the reference is GT 146

Please see them:
http://www.segel.co.uk/index.php?main_page=index&cPath=19_66_70

Is this correct?

Thanks for your time

Yes thats right!

Hi Gary

I have the DHW sensor now and I’ve read all your advises on this blog on how to swap it, but I’m still not sure how to uninstall the old one from the pump, do I need to pull the wires ??? I tried pulling them gently but they don’t come out, I don’t want to damage anything so could you please guide me?
Some users on this blog advise using some heat sink paste, is it really needed for the DHW sesor ? If yes how do you use it?
Please assume minimum technical knowledge.

Many Thanks
Tony

Hi Tony,

Yes you should use some heat paste around the threaded joint!

You should be removing the connections at the pcb board not the pump!

1, Make sure you isolate at the mains electricity,
2, Disconnect the orange connect plug from the pcb board.
3, using a small flat screwdriver insert in slot next the cable connection and the cable will come free, then install new connections in reverse order.

Kind regards

Gary
MK Group Ltd

Hey Gary thanks for your quick reply.

Let me clarify something:
The threaded joint is the DHW side that you connect to the hot supply pipe on the plate heat exchange right? On this end I'm using some PTFE tape ( like in the old DHW sensor ) do I also need to apply the heat paste?
If yes, how do you apply it?

Thanks
Tony

No need to use PTFE tape, just use the heat paste and wipe it around the thread prior to screwing it in!

Hi Gary

whoever installed this Pulsacoil 2000 8 years ago used some PTFE tape around the threaded joint, was this a mistake or it doesn’t matter?
If it doesn’t matter I’ll use some PTFE tape again as I already have some, if it does matter I’ll order some heat paste
Please let me know thanks

I would recommend heat paste but you can use ptfe

Kind regards

Gary
MK Group

Hi Gary

I'm unable to disconnect the orange connect plug from the pcb board, I tried to pull it but it just doesn't come out I must be doing something wrong ...
Any advise on this?

Thanks for your time
Tony

Make sure the mains are off!

Pull hard! Or alternatively call a professional.

Gary

MK Group Ltd

Hi Gary

I called a professional a while ago but because it's an intermittent issue he was unable to diagnose the problem, when he came over the boiler was working perfectly
When the boiler stops working I've noticed that the plate heat exchanger is stone cold like the water, then I switch off the boiler for 15 min and when I swith it back on I get hot water again and the boiler works perfectly for days, if I'm not wrong the plate heat exchanger should be hot all the time?
Could it be a problem with the plate heat exchanger? I live in an hard water area
I generally get this problem in the morning when the boiler has been inactive for a few hours by the time a call a professional the boiler starts working again, sometimes I dont even need to swith it off..
Have you ever come accross this kind of issue?
Thanks