Gledhill Pulsacoil fixed Monday 6/6/22

Gledhill Pulsacoil fixed Monday 6/6/22

Briefly, a letting agent I’ve never heard of left me a voicemail late on Sunday afternoon while I was bellringing for Sunday service, in the pretty little church of St Katherine in Savernake Forest. Having been somewhat messed about by letting agents in the past I decided not to ring back until the morning. Then first thing Monday morning the landlady (who is an old customer) texted me asking if I could help out their tenant in Reading who had no hot water from their electric hot water boiler, a Gledhill Pulsacoil. It turned out to be the same property the letting agent was calling about.

The Pulsacoil has a poor reputation but this is partly because few plumbers understand it well, and tend to advise people with them to replace Pulsacoils rather than repair them, even though they are actually pretty easy to fix in many cases. Anyway, I called the tenant to get a bit more information and to discuss the failure as there is one fault the occupier or owner can easily fix themselves and get their water back on immediately (the fault being lack of water in the header tank, which the user can add manually), to see if this might be the fix theirs needed. Unfortunately no it wasn’t and they knew about this already, so I arranged to visit later in the afternoon.

On arrival, whilst waiting for the tenant to clear everything of the boiler cupboard so I could get to the boiler(!), I turned on a hot tap in the bathroom to feel the temperature of the water. Now with a Pulsacoil if the store is hot, one still gets a brief slug of hot water from them before the hot tap runs cold even under fault conditions but this did not happen, which told me the Pulsacoil must be stone cold.

Once the cupboard was clear I took the front off the appliance and felt the metal of the electric immersion heaters and yes, the appliance was cold, when it ought to have been hot. This is the immediate cause of the fault – no hot water in the thermal store. The Pulsacoil can’t supply hot tap water when the thermal store is cold. So I knew the off peak immersion had stopped working. The usual cause of this is a tripped overheat protection thermostat, and removing the cap from the heater element to check confirmed this.

Nuisance-tripping of the overheat protection thermostat on the Pulsacoils is such a common fault that I made a video of how to reset it for anyone inclined to do it for themselves. Here’s a link . (Video is 2 mins 45 secs, and opens in new tab.).

Once the cupboard was clear I took the front off the appliance and felt the metal of the electric immersion heaters and yes, the appliance was cold when it ought to have been hot. This is the immediate cause of the fault – no hot water in the thermal store. The Pulsacoil can’t supply hot tap water when the thermal store is cold. So I knew the off peak immersion must have stopped working. The usual cause of this is a tripped overheat protection thermostat, and removing the cap from the heater element to check confirmed this.

There is a problem with re-setting a tripped overheat thermostat though – it tends to do it again so given a new thermostat is not that expensive, I prefer to fit a new one when I encounter this fault rather than to just re-set it, as I keep them in stock in the van. This option is not available to a user re-setting their own though (unless they happen to have one), so re-setting the existing tripped thermostat often still works perfectly well.

Given the tenants said they had had no hot water for a day or so, I asked them if they had tried the emergency ‘boost’ facility on their Pulsacoil. They didn’t know about it – unfortunate as it could have given them emergency hot water while waiting for a proper repair – so I explained. The emergency boost is operated by one of the three switch plates on the wall next to the Pulsacoil, which is often unlabelled so the user may not know about it. In fact one of the most common questions about Pulsacoils I am asked is about what the three switches on the wall each does. I’ll write a separate post explaining this in detail, watch this space!

So having fixed the off peak heater I showed the tenants how to use the daytime booster heater, advised them never to forget to turn it OFF after an hour as it uses expensive daytime electricity. They expressed some concern that I was unable to demonstrate hot water coming from the taps immediately but I explained this was because the store was still cold and with the boost heater now on, they would get some emergency hot water in around an hour, then unit would return to full functionality tomorrow once it had fully re-heated overnight. I gave them my number to contact me if this didn’t happen as predicted, but they have not called so it did, hopefully! I texted the landlady to let her know it was fixed and how much the bill was, and she paid me by card over the phone.

I have a separate website for the Pulsacoil packed with Pulsacoil information, here: www.pulsacoil-repairs.co.uk (Opens in new tab.)

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