Our hot water is too hot

[ChipsAndEgg]

Our hot water is too hot and I'm struggling to see how to turn it down. We have a normal boiler that feeds a hot water tank. The dial on the tank is at 60 degrees, but the water coming out of the tap is much hotter. The immersion heater is off (never used)

Our boiler is a Potterton Promax HE and the only controls on the outside is one solitary reset button. Our previous boiler (old house) had a dial on the front that controlled the hot water temperature.

Any ideas?

What colour is the hot water cylinder? (This is not a joke).

Is the heating turned off, and are any of the radiators hot?

How old do you think the gas boiler is, and when was it last serviced?

P.s.

Just to check, your boiler is a Promax, not a Promax Plus?

Can the dial go lower than 60?

If the hot water tank is square, or white or silver, it should have some names on it.

The dial can fo lower than 60 (55 I think is the min).

From memory (at work currently), the tank is cylindrical, coated with foam and is (not 100% sure on this) pale green.

The heating is enabled, but the thermostat is set to 10% so never comes on. Radiators are cold.

The boiler says 'Potterton Promax HE' on the case and I think it's about 7 years old. Last serviced about 12 months ago I think (we've only been here 10 months).

Have you tried turning it right down or does it stay the same?

Close to the boiler, or close to the cylinder, there will probably be a pump (probably dark red) and a 3-port valve (brass, with three large pipes going into it in a T shape, and with a rectangular box, probably metallic grey but might be plastic. The fault is probably in the 3-port valve head, which contains a switch, or in the thermostat which is strapped to the side of the cylinder.

Verify first that the immersion heater is definitely turned off. It might have its own circuit breaker of fuse in the "fusebox" that you can turn off.

Then turn the cylinder stat up and down. You should hear it click on and off. You might hear a whir from the motor in the rectangular box on the 3-port valve.

If I am right, the boiler does not have to be opened up (it is quite tricky on your model) and the fault can be fixed by changing the motor head. Unless you are fond of plumbing and electrical work, you will need a heating engineer. If you are really lucky it will be the cylinder stat but they rarely go wrong.

Until fixed, use the timer to turn the boiler on and off. It should be able to heat the cylinder from cold in about half an hour, and the cylinder will hold about a bathfull.

You may find if difficult to get that model of boiler serviced or repaired, so ask around for recommendations of a good local engineer. Avoid yellow pages, and especially avoid advertising recommendation websites.

My mistake, the cylinder us actually a golden yellow colour, does t going at make any difference? The immersion switch has always remained off and unlit.

When we used to have the heating on, the radiators were always extremely hot.

We had the problem you describe at our previous house, plenty of hot water but no heating. A new valve motor that out. Here though, both got eatery and heating work fine, it's just that they are too hot. Where would the temperature seeing for the radiator water be?

My mistake, the cylinder us actually a golden yellow colour, does t going at make any difference? The immersion switch has always remained off and unlit.

When we used to have the heating on, the radiators were always extremely hot.

We had the problem you describe at our previous house, plenty of hot water but no heating. A new valve motor that out. Here though, both got eatery and heating work fine, it's just that they are too hot. Where would the temperature seeing for the radiator water be?

Bah! Sorry for double post.

yellow foam insulated cylinder is quite old, might be 20 years or so. If you put a red jacket round it, heat losses will be reduced.

Green is newer, light blue is latest. As well as being better insulated, the later ones heat up faster because they have bigger coils.

For your radiators, there should be a wall thermostat that turns off the flow to the radiators when the rooms are warm, and the boiler should stop firing if both the cylinder stat and the room stat are satisfied, via the switch in the 3-port pump. I had a look at a pic of your boiler, and it does not appear to have a boiler temperature knob, it might be preset temperature, and there is a chance that the setting is wrong or failed. Use a thermometer to see what temp the hot water gets to if you leave the boiler on all day (though I would not recommend that as normal, since it may get scalding).

I am not familiar with your boiler, but it seems to have a difficult reputation and may be older than you think. however it seems to be a condensing and modulating boiler so probably fairly efficient, so no need to replace it unless it becomes irreparable. The 'Potterton Promax HE plus appears to be newer and not the same.

I think your might be this one but I can't see a date.

As mentioned before, try turning the temperature down and see if that makes any difference. If it doesn't, then have your system serviced and ask the engineer to check out the temperature on the tank. He may be able to give you an idea of the condition and age of the boiler.

Ours had a similar problem and it turned out that a valve had become stuck open, so the water heater wasn't cutting out (or something). It didn't cost that much to fix but was a job for a professional.

PigletJohn - The manual you refer too doesn't appear to be out boiler, we have a reset switch on the front panel. The bottom section doesn't hinge down either. hre's a pic I found on the web:

Our boiler

Thanks for all your suggestions, I'll get a local heating engineer in to have a look.

ah, that one is the "plus" which is apparently less troublesome.

if so, you can probably get a user manual from the manufscturer. Usually they are downloadable but I can't see their link.

The may be an identification plate or label on it, or behind a flap. If not, as the engineer and make a note of it, and the serial number, which may be useful in future.

ask on here