Fortic f1 direct hot water tank

playlister82

Does anyone know anything about these tanks?

I've just moved into a flat and it has an electric "fortic f1 direct" hot water immersion tank. I have never had one of these before, being used to gas combi boilers all my life, and I am struggling to get my head around it. I have figured out how they should generally work, including the timer functionality, but I seem to have a problem where there is never enough hot water for a bath. It consistently fills up to about 30 litres of steaming hot water then it just stops there. Does anyone know why it might be doing this? I don't think there is a leak or any air bubbles causing it. I feel like there could be a problem with cold water replenishing the tank properly, but I am not sure.

plumb1_2

Check the ball valve is filling it up fast enough, could be debris in the valve seating reducing the flow. Or any isolation valve not opened fully.

ThisIsWeird

Photo, please, showing all switches and cables. It won't have two immersion elements, will it? One high for a small, fast hot supply, and a low for a full tank?

Or a twin-element one at the top?

playlister82

These are the best photos I could get

playlister82

ThisIsWeird said:

Photo, please, showing all switches and cables. It won't have two immersion elements, will it? One high for a small, fast hot supply, and a low for a full tank?

Or a twin-element one at the top?

I think it has two immersion elements one at the top and one at the bottom

ThisIsWeird

Cool - that could be the answer.

How are they controlled? 

You understand what each one does, their individual purposes?

Do you have low-cost overnight leccy?

playlister82

ThisIsWeird said:

You understand what each one does, their individual purposes?

Do you have low-cost overnight leccy?

No I don't really and that's the problem. Like I've done some research online but it's hard to find all the answers.

As for electricity, I am on a standard variable rate...does that make a difference?

ThisIsWeird

In essence, you'd heat up the whole tank - via the lower heater - using the cheapest rate of leccy you can get. You would then fire up the upper immersion if you still required an added, but smaller, 'top-up' amount of hot water.

You might even find that the top immersion will be enough for most use, or on some days, say you only need a basin-full for a wash, or to do the dishes. Obviously, the less water you heat up, the greater the savings. These are well-insulated tanks, tho', so if you were to heat the whole tank, but only use a quarter, it should remain hottish for the next day - the immersions will (should) have thermostats in them to stop heating when the water temp reaches typically around 60-odd degrees. Some folk even leave the immersions permanently switched on, knowing that it's effectively 'off' - not heating - as long as the water is hot.

If you are on a 'standard' rate, then I presume it doesn't make any difference when you fire up the heater(s). Homes powered solely by electricity will usually be on a dual-tariff, controlled by a programmer or timer, so that things like the hot tank and storage heaters are charged up at the lower rate.

What Central Heating do you have - how do you heat your flat? Can you show us pics of the immersion switches - any timers on them? And of your electricity meter.

playlister82

This is the only switch that is linked to the tank. Both leads from the top and bottom heater connect to it. Does that mean it's a twin immersion heater and not top/bottom as we've said? Sorry, I don't know anything about these things.

When I press "boost" the water starts heating immediately and for the length of time selected. I haven't used this option yet because I vaguely understand it would be expensive - should I use it?

Without boost the water just heats when the timer is on. At these times, I've noticed the "economy" light lights up.

Now I would have thought that the timer hours - around 4 hours at night and 4 in the afternoon - would be enough to give me a full bath, but it isn't. The hot tap on the bath always stops running after 2 to 3 minutes leaving me with a quarter bath full. Nothing I've tried with the timer seems to make a difference. Does that make sense?

The flat's heating runs on storage heaters, as far as I understand they store heat at night and let this out during the day.

grumbler

I think with this controller you can program the bottom element ON time  while the top element is permanently on. If the water at the bottom of the cylinder is never hot, then, possibly, the bottom heating element is faulty.

https://www.manualsdir.com/manuals/373607/timeguard-trtd7.html?download - a manual for more modern version of this controller with digital timer. I think everything except programming it remains the same.

ThisIsWeird

Probably as Grumb says. I certainly haven't a clue how these are wired up.

'Boost' certainly suggests a quick, small quantity, lump of water, so this will be the top element and at full leccy cost.

The 'timed' heating might power just the lower element, or both, I don't know. But it seems pretty clear that the bottom element is not working.

Could be the element itself, or the thermostat that controls it.

There are a couple of 'safe' tests that a layperson can carry out if inclined?