The Pulsacoil Stainless Mk2 is the third generation of Pulsacoils from Gledhill with a stainless steel internal tank, the first also being called confusingly, the “Pulsacoil Stainless”. I refer to this latest version as the Mk2. All models without the word “stainless” in the name had copper thermal store water containers inside which are far more prone to pinhole leaks.
The new “Pulsacoil Stainless” (Mk2) model is completely different in appearance from the previous “Pulsacoil Stainless”. The old one is in a neat, tidy rectangular steel case with all the vulnerable parts (pump, circuit board, heat exchanger) neatly contained and protected within the metal case. The new Pulsacoil Stainless Mk2 is round in format, with pump, circuit board and heat exchanger attached to the outside, admittedly under a large plastic cover, but more prone (in my opinion) to impact and damage. Topographically it appears to be similar to the Pulsacoil Stainless ECO, but with a flow limiter after the mains water inlet strainer and a check valve in the return pipe from the plate heat exchanger. All the components are arranged differently though, presumably to reduce manufacturing costs.
Common faults and fixes:
Firstly I need to point out this is a brand new model introduced in, I believe, January 2020, so if you have one it should still be in guarantee. But here are the faults and breakdowns to which I think they will be prone, having carefully read the manual and looked at the photos and parts lists:
1) Heater element failure
The heater elements are the same as most previous models of Pulsacoil and although they rarely actually break and stop heating, they leak. The thermostat pocket corrodes through and water escapes into the wiring connection box and sometimes into the thermostat itself, either blowing fuses or causing the overheat protection thermostat to trip.
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, the y can be damaged by water ingress when the 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.
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 time consuming the chemicals are not cheap. The most economical fix is to fit a new heat exchanger.
If you need a repair to your Pulsacoil STAINLESS Mk2, call or text me on my mobile 07866 766364.
Copyright Michael Bryant 2020
Site first published 2nd January 2007
Last updated 25th February 2020
Gas Safe Register 197499, CIPHE registration number 56207