Pulsacoil 2000 - another case of cold water

Hello Mike,

I have a Pulsacoil 2000 boiler which has now cost me a lot of money, time and anxiety. There have been problems previously but everything has been okay for the last couple of months. In the last week or so however the hot water has gone again. There is a small flow of very hot water but barely enough to fill a sink before it goes cold again.

History is as follows:

First problem was around 9 months ago - no hot water so called out "Millenium Electrical". Engineer said it was the pump and replaced the pump; that seemed to work for a while. (about £200)

Second problem was around 3 months ago - no hot water so called out "Millenium Electrical" again. Bottom heating element had gone so as a temporary measure the engineer wired up the top one, switched it on, started to heat up, so he left. (£145)

Next day, water was still not hot so I asked the electrician to come back. In the meantime, I drained the tank, bought a new heating element and replaced the faulty bottom one. Filled the tank back up and got the electrician to check the wiring - which he did and kindly charged me another £85.

The following day it stopped working again so I called somebody more reputable (Pimlico Plumbers). Whatever he did, it started working again but he claimed he didn't have to do anything, just checked all the wiring (£120)

It has been fine until last week when the hot water has stopped coming through again. I bought a new thermostat for the bottom heater and replaced that today but that hasn't made a difference.

The electrics (PCB, sensors, etc) are a bit beyond me and I'm wary of fiddling too much there without the appropriate electrical knowledge but it seems to me that the heating elements may not be working or perhaps the stat has tripped. When it fires up, it heats for a few minutes and then stops again. This continues sporadically so I am assuming the water does not heat up. The outside of the tank is not getting that warm and there is only a tiny amount of hot water coming through.

If I turn the hot tap on for a minute or so then all the hot water out (DHW) pipes are cold again.

Another strange thing is that even though (I'm pretty sure) the bottom element is heating the tank, the warmest part of the outside of the tank is near the top.

I haven't checked the tank level but will do that later today and I am not sure where I can buy a replacement sensor if that is the fault.

I am quite desperate now. I've spent a huge amount of money on this boiler and don't want to spend any more money than I have to and also I definitely don't want to spend any more money on people that are not familiar with the workings of the boiler.

Please could you let me know if you are able to troubleshoot via e-mail / forum, or if not are you able to come to South West London (Wandsworth). If this is too far, then perhaps there may be somebody that you know and trust who will come to my area.

I look forward to hearing back soon.

Thanks,
Richard (London, SW18)
07775 562363

Hi Richard,

This sounds very unfortunate. I think the DHW sensor (the upper one) is failing and has been all along. You can buy a new one mail order and fit it yourself from these people: http://www.segel.co.uk/index.php?main_page=index&cPath=19, or yes I can come and do it for you and fix anything else at the same time that may turn out to be wrong.

Wandsworth is an easy drive from here in Reading. Give me a call on my mobile, leave me a message and I'll call you back. (All calls go to voicemail to intercept the spam calls.) My number is 07866 766364.

Cheers, Mike

Hi Mike,

thanks for your advice. I bought a DHW sensor yesterday and attempted to fit it today. There is a brass threaded fitting with a brass nodule on the end of the one I purchased but the one I attempted to replace was just a wire with what seemed to be some kind of coating on the end. This was held into a 10-12mm outlet with a small rubber tube-like seal. I have sent you a couple of pics by e-mail so you can see how the existing sensor fits in to the DHW out pipe.

Not sure what to do and if my pipes are unusual for this particular model (Pulsacoil 2000).

Any advice would be greatly appreciated.

Thanks,
Richard (07775 562363)



http://mail.google.com/mail/?ui=2&ik=f9755586bf&view=att&th=1202464276485820&attid=0.1&disp=inline&zw

The sensor you described is the GT146 or GT147, you can order either one which will work. I would personally recommend the GT146 as it slots in the tube more easily. You can find it on line via this link: Gledhill Pulsacoil 2000 Spares