Advice really appreciated on hot water temperature

[JanetD123]

Hello people in the know! I have just moved into a new house. It is a system I am not used to as my previous home had a combi boiler. So, there is a large blue hot water cylinder in the airing cupboard and the dial on the front is set to 65. There is a Valiant Ecotec 418 Boiler in the kitchen and the water dial is set to 65 (it doesn't go higher than this).
I have the water set on a timer to come on at 5pm for one hour.
It just doesn't seem hot enough. So . . . can I turn up the temperature on the front of the blue hot water cylinder or is it governed by the 65 setting on the boiler. Also, how long should the water stay hot for? The system was installed by the previous owner in 2014.
Many thanks for any advice you can give. All the best Jan

 

[Aire]

The cylinder thermostat should be set at 65° so no need to change that. Your likely not timing your hot water for long enough. How big is the cylinder?

 

[JanetD123]

Hi Chris - thank you for your reply. Its a big one! (see pic) My neighbour has had a look and says the pipe to the tank from the 3 port valve(?) is hot so thinks my boiler is faulty - but he's not a gas engineer so I wanted to get some advice before calling out an engineer

 

[snowhead]

Ah, another Brexit stockpile...

How hot does the water get, hand hot or colder?
What time are you trying the water?

As per Craig, it's not on for long enough if it's only on for an hour a day.

If you need it for 5pm, try setting the timer for 3.30pm and see when it gets hot enough.
Adjust the time if you think it's too early.

 

[JanetD123]

LOL @ Brexit stockpile! Hand hot but not hot enough that I need to pull my hand away.
My sister has a similar system but only has her water on for half an hour and its roasting! Ho hum.
Thanks snowhead . . . will try to put it on for longer

 

[SimonG]

Run it longer, once up to temp it will shut off.

 

[Aire]

Hi Chris - thank you for your reply. Its a big one! (see pic) My neighbour has had a look and says the pipe to the tank from the 3 port valve(?) is hot so thinks my boiler is faulty - but he's not a gas engineer so I wanted to get some advice before calling out an engineer

Hi Jean you don't have a 3 port valve, you have zone valves. When the timer is calling for hot water then the pipe should be hot to the cylinder, if your hot water isn't on but your heating is then it could also be convection heating the pipe up. If your unsure or concerned then best to call an engineer in to check the system over.

 

[JanetD123]

Thanks Simon G - will try the 1.5 hours as Simon suggested . . . Craig . . . I just let him come in for a look in case it was an easy fix, but tbh I probably wrote it down wrong! Thanks guys, really appreciate your help

 

[johnduffell]

if the boiler only supplies water at 65c the cylinder would take a while longer to get up to temperature, traditional boilers would go up to 80+. If that's as high as it goes you'll have to give it plenty of time.
However having said that all the pipes around the valve should be red hot when it's running so it could be either a circulation or a valve issue.

 

[rpm]

Not trying to get you to spend money however when was it last serviced? Maybe a service and a full explanation of what`s what would help you.

 

[fezster]

The water being 'hot enough' is subjective. You could measure the temperature at the hot tap - it will probably be roughly 10 degrees lower than the cylinder is set to, because of heat loss before it gets there.

If your boiler is only set to 65 degrees, though, it'll short cycle before the cylinder has fully heated up. The boiler flow temperature should be roughly 10 degrees higher than the cylinder stat temperature to allow adequate heat transfer.

 

[Welder]

if the boiler only supplies water at 65c the cylinder would take a while longer to get up to temperature, traditional boilers would go up to 80+. If that's as high as it goes you'll have to give it plenty of time.
However having said that all the pipes around the valve should be red hot when it's running so it could be either a circulation or a valve issue.

It's the cylinder stat that's set to 65 not the boiler

 

[chris watkins]

Janet has your Vaillant got the two temperature dials on the front (one Rads & one Tap) if so what temperature do you have set for the rads ??

 

[chris watkins]

The hot water (tap) dial on your boiler has no effect, it is not used in this country on the regular or system boilers only the comb's.
You will need to have the heating (rad) one turned up to at least 70 so it can heat the domestic hot water up to the required 60 -65 deg C.

 

[johnduffell]

It's the cylinder stat that's set to 65 not the boiler

A can't disagree, I was just taking the op on face value that there were two and both set to 65c!

or is it governed by the 65 setting on the boiler

there is a large blue hot water cylinder in the airing cupboard and the dial on the front is set to 65.