Fortic f1 direct hot water tank

playlister82

ThisIsWeird said:

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

What are these?

playlister82

Also could someone confirm if it's normal for one of these immersion tanks to only give out about 30 litres of hot water at any time?

Whenever I run the bath, it's always exactly the same no matter how long the tank has been filling up / heating for.

I've checked and both the top and bottom heating elements are working. So based on this discussion, I have narrowed the problem down to the ball valve somehow not working, or one of the other valves.

ThisIsWeird

As Grumb has suggested, almost certainly only the TOP immersion element is functioning. That means that only the TOP of the tank will be heated = whatever litres you get out before it goes cold.

The 'test' is to - safely - remove the cover on the immersion element - with the power switch turned off - to expose the thermostat underneath. Turning the wee control - it should have a pointer on it, and a temp scale around it - back and forth until you can see where it 'clicks', will indicate the cylinder temperature at that point, whether the suggested temp makes 'sense', or whether it actually 'clicks' at all.

You WILL be exposing potentially live wires by doing this, tho' the power should be turned off throughout.

Do you know what a 'thermostat' is, and what it does?

plumb1_2

playlister82 said:

I've checked and both the top and bottom heating elements are working. So based on this discussion, I have narrowed the problem down to the ball valve somehow not working, or one of the other valves.

I am surprised 

ThisIsWeird

plumb1_2 said:

playlister82 said:

I've checked and both the top and bottom heating elements are working.

I am surprised 

Oops, I missed Playlister saying this. I'm surprised too.

If it's a failed or stuck valve, the symptom would surely be that the water flow would slow down and stop. Please don't tell us that is actually what you mean!

PL, how did you check the elements? 

plumb1_2

ThisIsWeird said:

plumb1_2 said:

playlister82 said:

I've checked and both the top and bottom heating elements are working.

I am surprised 

Oops, I missed Playlister saying this. I'm surprised too.

If it's a failed or stuck valve, the symptom would surely be that the water flow would slow down and stop. Please don't tell us that is actually what you mean!

Yes exactly 

ComicGeek

Those cylinders have a cold water header tank built into the top that feeds the cylinder below - was supposed to be a space saving option for flats without loft spaces for tanks. 

ThisIsWeird

Cheers, CG, and re-reading the OP's OP, it could well be that they're saying it simply runs out of water flow.

PL, they should have a removable top lid - could be snapped on, but see if you can lift it off. If you are uncertain, then look it up on t'net and see how it's done.

See if the ball valve is working smoothly, and whether there's dirt and debris in the top tank. Shine a torch in, and see if you can spot the outlet to the lower cylinder - is it clear?

playlister82

Yes that's what I mean - it slows down and stops after about 3 minutes every time.

The top of the tank is impossible to get to as it's right under the ceiling in a tight space. So I don't know how to go about that.

I've spoken with the landlord and she just thinks the tank has limited capacity that suits a shower rather than baths. Sadly I am a bath person!!

Anyway she has contacted a plumber to see what they think, but I don't hold out a lot of hope at this point.

ThisIsWeird

playlister82 said:

Yes that's what I mean - it slows down and stops after about 3 minutes every time.

The top of the tank is impossible to get to as it's right under the ceiling in a tight space. So I don't know how to go about that.

I've spoken with the landlord and she just thinks the tank has limited capacity that suits a shower rather than baths. Sadly I am a bath person!!

Anyway she has contacted a plumber to see what they think, but I don't hold out a lot of hope at this point.

Clearly it was installed by a genius!

When you run off a decent amount of hot water, can you hear it refilling ok? What does it sound like - a trickle or a good flow?

The LL is clearly wrong in any case; just look at the size of the hot cylinder part - you should be able to have that much of hot water, constantly replenished by the small CWS on top, which in turn should be filled at a rate to easily keep up with this (almost certainly it'll be supplied direct from the mains - unless there's another CWS on the roof/loft space?). On that note, what is the flow from your cold kitchen tap like?