Best way operate Pulsecoil hot water system with pics

sat_mad

Hi,

A relative has recently moved into a rented flat that has a Pulsacoil III installed for the hot water.

Please could someone explain how to best operate the system as there are no instructions, and the agency are not forthcoming with an answer?

- The picture shows the four switches present - the top operates a 'Boost' for up to 2 hours.

- The second appears to switch on the Pulsacoil.

- The third is marked Boost, and this switch and the fourth don't have an obvious effect when turned on, but are marked Water Heater.

There is also a Boost button on the electricity meter (Google says this is due to a dual electricity tariff.

Which switches should be turned on (and when)? Does the Boost button the meter need to be pressed at any point, or does the top switch operate this?

Many thanks.

nofoollikeold

Nobody can tell for sure without being there, but:

1. There are normally two immersion heaters fitted.
1a. The bottom one runs off cheap rate electricity, which is only on during the off-peak period, probably midnight to 5 am. Being at the bottom this heats the whole cylinder full of water.
1b. The top one runs off normal rate electricity and heats about the top third of the cylinder.
2. It is most LIKELY that:
2a. The very bottom switch is the cheap rate on / off, connected to the lower immersion heater.
2b. The second switch up, with the handwritten "Boost" on it, is not connected to anything. Possibly an old boost function.
2c. The switch (not the Horstmann) at the top of the three probably runs the electronics of the Pulsacoil and supplies power to the Horstmann programmer above it.
2d. The Horstmann programmer shows what is running, and also has the Boost button.

3. I'd suggest the normal mode of operation is to have all three switches in the on position (they are all off in your photo). Each immersion has a thermostat, so that when the preset temperature is reached, it switches itself off. Try and avoid using the boost button, as the electricity it uses costs two or three times the off peak rate.

4. The Pulsacoil is what is called a thermal store. The whole cylinder is (or should be) full of very hot water. When a hot tap is opened, cold water from the mains flows through a separate coil inside the cylinder, and this cold water is heated from the large body of hot water surrounding it as it flows through. Thus you get hot water at mains pressure. On some, the cold water flows though a separate heat exchanger on the side of the Pulsacoil rather than through an internal coil. I can't remember which the Pulsacoil III has, but it doesn't matter for these purposes.

5. The Horstmann programmer can be used to determine during which off peak hours the cylinder can be heated. Its a bit of a fiddly procedure, but you can get get the instruction off the internet. For now I'd suggest leaving it alone.

6. There is likely to be a top up tank above the main hot water cylinder, probably without any overflow pipe and without any means of re-filling it. This small tank must have water in it for the cylinder to work. Top it up with a bucket of clean water if necessary. There may be a very flimsy (often collapsed) cover over the centre of the small tank.

sat_mad

Thank you so much for taking the time to reply.

Now I have an idea of how it works, I'll take a closer look when I next visit them as I hadn't realised that there were two tanks in the Pulsecoil - though makes sense given the size of it.

I believe they have just been switching everything on (including the Boost) and hoping for the best, but it sounds like this could be an expensive mistake.

Thanks again.