Hotwater problems. Pulsacoil

Hi, My client has a 144 litre Pulsacoil. I have replaced both the immersion heaters, the tank (at 15.15 today ) is over 40 degrees C at the upper immersion heater body, but the tap water is barely tepid. I am in the London area where the water is VERY hard, and the unit is around 15 years old. What should I be looking at?

Thanks for your advice in this matter,
Regads, Brian the boiler fixer.

Hi Brian,

Well first thing is the store should be up at 75-80 degrees C, not 40 degrees. Turn the heater stats back up to MAX!

Water coming out should still be more than warm. Could be scale in the HE or a failed blender valve. Does the water start hot then cool off/slow down rapidly or is it cool all the time? The former indicates scale and the latter the blender valve. Descale if necessary using a powerflushing pump and Kamco ScaleBreaker SR. Takes about an hour of pump time.

Cheers, Mike

brian the boiler fixer wrote:Hi, My client has a 144 litre Pulsacoil. I have replaced both the immersion heaters, the tank (at 15.15 today ) is over 40 degrees C at the upper immersion heater body, but the tap water is barely tepid. I am in the London area where the water is VERY hard, and the unit is around 15 years old. What should I be looking at?

Thanks for your advice in this matter,
Regads, Brian the boiler fixer.

Thanks for that reply. You were spot on with both answers!

I descaled the HE, could feel and see the increase in speed of water circulation.(clear hoses on descaling pump). Also ran fresh water into my flushing pump, which heated up beautifully, even though the immersion heater had been off the previous night.

Re-built the system and found that the tap water still only ran luke warm:-(

Replaced the blend valve, and Bingo!!! Lashings of steaming hot water and two very happy flat dwellers.

Regards,

Brian the (central heating) boiler fixer.

Hi Mike, I have been called back into the Pulsacoil I fixed back in January. The tennant claims that there is no hot water at all. I have checked the immersion heater, in case the overheat stat popped, but that was OK. I noted the night rate meter reading and requested that he phone me this morning to give me the new reading.(I was suspecting that the economy 7 was not working) but he just phoned me and the system had used 7Kw-hr overnight, but he reckons that he only got 30 seconds hot water this morning.

Any bright ideas? Help.

Regards,

Brian.