Boiler Temp

Chickenman1108

Hi all
Not sure if I'm in the right forum but hope you can help me.
Recently moved into a new property.
Everything is currently covered by the builders' warranty.
I'm having trouble with my hot water. Problem is, it's just not very hot.
My shower has it's own thermostat so the temp on this is just fine.
But both my kitchen and bathroom sink just dont seem to get hot water.
I have a combi boiler.
I have checked the pressure and that's all fine.
I took a temp reading last week and after running the tap for over 2 minutes the water was coming out at 113F. The reading on the boiler itself was 44C (which I believe is approx 113F also). The dial is turned to MAX for water temperature.

My builder is saying that's perfectly fine but to me this isnt hot - it's just warm.

Strangely, if my heating is on also (also through the combi boiler) the water reaches much higher temperatures, but obviously my heating isn't on all of the time.

Does anyone know if there is some sort of "industry standard" for water temps? Should my boiler be reaching a certain temp when it is supplying just water (not heating)??

Many thanks for any help

daveyjp

Boiler make and model?

Our Vaillant will supply water at up to 65 degrees, set to 50 at the moment, we reduce this to about 45 in summer and it is always more than hot enough.

Norman_Castle

My shower has it's own thermostat so the temp on this is just fine.
But both my kitchen and bathroom sink just dont seem to get hot water.

Turn the taps down to reduce the flow to give the boiler chance to heat the water.

Chickenman1108

I know it's an Ideal Logic Plus combi boiler. Not sure of the exact model number but I will check this out when I get home.

I've tried reducing the flow. It makes no difference :-(

nofoollikeold

1. Your boiler is capable of heating a specified volume of water (litres per minute) from cold to hot. The volume, and the hot and cold temperatures, will be in you boiler manual. The flow rate is usually expressed as the volume in litres per minute that the boiler can raise in temperature by 35 degrees (Celsius). In winter, when the cold is colder, the hot will be at a lower temperature for the same rate of flow than happens in summer.
2. If you try and run off a higher volume of hot water, then it won't heat it to as high temperature. As Norman Castle has said above, turn down the flow to give the boiler a chance to heat a smaller volume to a higher temperature.
3. It may be that your shower doesn't use more hot water than the boiler can supply, hence why the shower hot water is hot enough.

PhilE

You really want it at 60C min, to kill any bugs.

Your builder is talking absolute nonsense.

There's an issue with the boiler, contact the manufacturer and/or get yourself a good heating engineer.

Le_Kirk

Chickenman1108 wrote: »

Strangely, if my heating is on also (also through the combi boiler) the water reaches much higher temperatures, but obviously my heating isn't on all of the time.

This doesn't make sense to me. With a combi, if the heating (radiators) is calling for heat (thermostat not satisfied) the boiler will fire and heat the water. If you then run a hot tap (basin, sink or shower) the diverter valve should divert all water to DHW. You are saying it is the other way round. I agree with others that you need someone (heating engineer) to look at it.

daveyjp

It may be the boiler isn't suitable. Builders buy job lots of a single type of boiler for discount and fit. They never do the calculations to ensure it is the right one and will always buy the cheapest.

It may therefore simply be the boiler is underpowered for the cold water pressure.

When you know the model look up the capacity to heat water. It will state x litres per minute. The latest model C24 has a hot water output of 9.9 litres a minute.

https://idealboilers.com/installers/products/logic-plus-combi#techspec

Check the water pressure. See how long it takes to dispense a set amount. A litre, or even better 5 litres and use this to calculate litres per minute.

If your cold water pressure is a lot higher than 10 (ours is nearer 15) the volume of water is simply too high to be heated. It is probably OK for a short time when heating is on as the water is inside the boiler pipework. I know the hot water from ours is scalding when the heating is on, then as cold water enters the boiler it settles down.

You will either need to turn down the stop tap to get the pressure near to 10 and live with a lower flow of cold water, or ask for an upgrade to the boiler to one which meets the mains water flow.