PulsaCoil ECO Stainless 150 - Insufficient Hot Water for Shower since Installation in 2017

My PulsaCoil Stainless ECO 150 heating system was fitted when this retirement village complex first opened in 2017 and I have been the only occupant of my flat since that time.

I have often complained about the insufficiency of hot water for the shower on several occasions and each time have been told that this is the way that the system is designed: I have difficulty believing this explanation. Typically what happens is when I have a shower I habitually start shampooing my hair straight away but by the time I'm following up with conditioner the water is going tepid, then cold. At this point, as firmly advised, I don't shut down the shower but keep it on, whereupon the warm, then hot, water returns after a minute or two. I think this strange cycle of events would repeat, but haven't ever stayed in the shower long enough to find out!

Can anyone please tell me whether this is this really what is to be expected from a PulsaCoil system? It seems to me to be far more likely that some kind of temperature interlock is intervening - perhaps within the thermostatic valve within the shower? Thank you!

Margo

I would imagine your experience is not how the system is designed to work. You should have a large reservoir of very hot water and when you turn a tap on the system will detect this and start the plate heat exchanger pump to push the water through the heat exchanger to keep the water hot. With a large tank of hot water you should be able to enjoy a long hot shower. OK diagnosis do you have the same effect if you turn on a basin hot tap i.e. hot then cold then hot. If yes there is a system issue, if no then the shower mixer is probably at fault. If the system is at fault then I would give Gledhill technical a ring to see what they think. I have no real direct experience of this system but if it is similar to many of the other Gledhill systems it will probably control the speed of the plate heat exchanger pump to try to maintain a safe hot water temperature. The speed is controlled by a pcb with sensors in various bits of the system. The manual gives some limited information on operation.

https://www.gledhill.net/uploads/PulsaCoil-Stainless-Manual-1.pdf

Regards Murray

Many thanks for your swift and valued reply, Murray. The hot water taps for the basin have never exhibited the same problem (indicating that the shower value may indeed be at fault) - that said, one never runs a huge quantity of hot water through a tap in one go. Next time my son visits, we'll take a closer look and report back within this forum. That will take a couple of weeks.

Thanks again,
Margo

Your welcome, yes I think you will have to give a hot tap a good run to see the result properly, if you have a bath that is a good reason to have a good hot soak maybe (-

Regards Murray

Hello Margo. Whereabouts in the country are you? If you are in a hard water area, it's possible that your plated heat exchanger has many of its plates scaled up. What happens is that the water simply goes through the plates that are clear, so there is little exchange of heat. As previously suggested, it's best to run a tap to see if it happens from all outlets. If it's your shower only (that is affected) then I would suspect that it's the shower thermostat. If, however, you get this from a tap as well, then either the sensor isn't telling the pump to run fast enough (to send hot water through the plated heat exchanger, and thus exchange the heat) via a printed circuit board, or it's limescale. I will wait to hear what you say. If you are reasonably close to me (and it is limescale) I can descale plated heat exchangers (please see www.scalgon.co.uk). If you are some distance away, then it may be more economic for you to employ a local engineer to replace the heat exchanger. You can get them for as little as £114 (plus the supplier's mark up charge) and I would suspect a labour time of around 2-3 hours, so you could expect to pay £140 - £200 at a guess. That would therefore be a total of maybe £300+. I descale this type of thermal store for a set fee of £229 all inclusive...BUT that's only if you are within my postcode area 'RG'. If you're outside, then I make a mileage charge. If you would like to email me direct, please do so on info@scalgon.co.uk or you can text me on 0770 231 6157. If you are to the west of me (I'm in Reading, Berkshire) then you may want to give MikeTheBoilerman a call (who runs this forum) if you want the heat exchanger replaced.

You should also be aware that these type of heaters aren't limitless in their ability to supply hot water. They have a store of water to use up. The 150 litre store (for example) will drop from 55 degrees to 35 degrees after 10 minutes of running water at a standard flow of 1 litre every five seconds. I suspect this isn't the case where you are concerned as I don't expect you are running it for that amount of time. However, it is something to remember with 'rain' showerheads.

Regards, Barry.