The Pulsacoil Stainless is the first in a new generation of Pulsacoils from Gledhill with stainless steel internal storage tanks instead of copper. All previous models had copper tanks inside which in the long term turned out to be terribly prone to pinhole water leaks. With no access to the inner copper tank through the riveted external steel case, these pinholes could not be fixed so a whole new appliance was necessary.
Technically it is very similar to the previous model the Pulsacoil A-Class, using what appears to be the same external heat exchanger, pump, sensors and a very similar electronic control board. The user control panel with it’s ON/OFF switch and “Boost” button with built in timer have been dispensed with though, so these functions need to be installed externally by the fitter if required. The heater elements are a little different too, having a 1.25” BSP mounting thread instead of the 1.5” thread of previous versions. This means it is no longer possible to fit a cheap low quality generic heater element to replace the high quality, ‘low Watt density’ elements factory fitted originally, should one fail.
Common faults and fixes:
1) Heater element failure
The heater elements in older versions tended to fail from copper corrosion and water leakage rather than electrical failure, but the elements fitted to the Pulsacoil Stainless have no copper components so I am expecting this problem to have been ironed out. It is still possible for the element conductor itself to fail but I have yet to see this happen with this new copper-free type of element.
2) Thermostat failure.
The thermostats in the heater elements fail, in several ways. They can lose their calibration and turn OFF at too low or too high a temperature, they can be damaged by water ingress if the immersion heater pocket holding them leaks, the integrated overheat protection built into them can randomly trip occasionally needing re-setting, or the overheat thermostat can trip correctly when the unit is overheating. A new thermostat fixes all these things except the leaking element pocket, which needs a new heater element too.
3) Scale contamination of the heat exchanger
The water flow from taps falls down towards zero and at the same time, what water flow there is, emerges cool. This happens when water scale gets deposited on the inside faces of the plates in the heart exchanger. The scale can be chemically removed but this is rather time consuming the chemicals are not cheap, so the most economical fix is to fit a new heat exchanger.
4) Low water level in the header tank
As with all Pulsacoils the header tank needs to be topped up with more water to the correct level periodically. With the Pulsacoil Stainless this could be as infrequently as every few years but eventually, as the water level slowly decreases, the hot water will eventually stop working. To start with the hot water will work intermittently, but the intermittent failures will grow more frequent. There is a sight gauge on the front of the header tank and if checking it shows the red indicator float at the bottom of the gauge, add more water. It could take several buckets of water to get the level up to near the green line, as shown in the photo.
If you would like me to visit and fix your Pulsacoil STAINLESS, call or text me on my mobile 07866 766364.
Copyright Michael Bryant 2020
Site first published 2nd January 2007
Last updated 1st February 2020
Gas Safe Register 197499, CIPHE registration number 56207