Increase water temp?

knightstyle

We recently moved and have a Greenstar Gr2300iw 25 C Ng combi boiler. The hot water does not get hot enough, I have tried but cannot get the boiler to go above 60C. So the water in the kitchen, at the other end of the house, is not hot enough to wash up.
Is there a way to sort this?

ButterCheese

Don't touch the boiler yet.  There is a reason it won't go above 60 and that is because it's not meant to.  When we've had new boilers installed, they have always set it to 58 and told me not to change it.

I would suggest getting a boiler engineer in and getting some professional advice, as it sounds like there is an issue with the boiler.  Do you know how old it is? 

FlorayG

Is it hot enough near the boiler? If so you have the same problem I have, it needs to heat a great length of pipe before you get actual hot water. If I run it for a while it does get  hot. My boiler is about 30 feet from the kitchen!

FreeBear

FlorayG said:

Is it hot enough near the boiler? If so you have the same problem I have, it needs to heat a great length of pipe before you get actual hot water. If I run it for a while it does get  hot. My boiler is about 30 feet from the kitchen!

Same here. Very long run of pipe to the kitchen, but a short run to the bathroom. Almost instant hot water for baths & stuff, but a long wait in the kitchen. So I have my water set to ~45°C, and when I need hot water in the kitchen, I'll boil a kettle - On the face of it, sounds inefficient use of energy, but I'm not wasting gas to heat ~10l of unused hot water that would remain in the pipes & boiler.

And yes, most modern boilers will limit hot water to 60°C - Even at that temperature there is a real risk of scalding, and there should be thermostatic valves on all taps to limit the temperature.

eddddy

As you probably realise, the combi boiler will be heating water coming directly from the mains as it passes through the boiler.

Mains water is coming from outdoor underground pipes and is probably colder than usual at the moment, due to the cold weather. So the boiler might be struggling to heat it to 60C. (But if that's the case, you would probably notice the same issue with showers and baths.)

And as above, there might be a lot of cold water and cold copper pipes between the boiler and the sink.

If the boiler is struggling to heat the water to 60C, you can try experimenting with reducing the flow (i.e. not turning the tap on fully). The water will flow slower through the boiler, so the boiler will have more time to heat it up. But obviously, the washing up bowl will take longer to fill.

casper_gutman

It's normal for taps at the far end of the house from a combi boiler to take a long time to run hot. Ours does this. But once it comes through it's quite hot enough. Are you saying yours never gets acceptably hot no matter how long you run it? If you have a thermometer available, how do the temperatures of hot water from the kitchen tap and from a source closer to the boiler compare?

sheenas

The water temperature should be between 50-60c, now if you are adding cold water then reduce the cold flow If its still very slow then maybe the boiler needs a service.

ThisIsWeird

The operating instructions suggest that the DHW temp can be adjusted, but I don't know what the max is.

Knightstyle, could you press the wee 'tap' symbol, and see what temp displays? That should be the DHW 'set' temp.

Now run a hot tap, and see how the displayed temp compares - I suspect it'll start lower, but should build up to the 'set' temp. Does it?

(You said you tried to increase the temp - is that what you meant? And the 'set' figure won't go higher than 60oC? But what does the actual 'flow' temp show when a tap is running?)

ThisIsWeird

As said by others, the incoming mains water will be a good few degrees cooler at the moment, and a 25kW combi isn't a large size, so if the flow rate through the tap is excessive, then that could explain a less-than-60oC temp. But, as also said, once the boiler is up and running, and the hot supply has fully reached the far-away taps, the hot water should be just as hot coming out your kitchen tap as nearby ones.

So the Q is - what does the actual 'flow' temp show as being when a hot tap is open? If it goes up to the 'set' 60oC, then it's likely just a case of the kitchen tap not having been run for long enough for the full 60oC to come through. 60oC is 'hot', very 'ouch', serious risk of scalding with a few seconds contact.

FreeBear

ThisIsWeird said: (You said you tried to increase the temp - is that what you meant? And the 'set' figure won't go higher than 60oC? But what does the actual 'flow' temp show when a tap is running?)

Specifications for the boiler state DHW temperature range of 35-60°C. So it can't be set any higher.

knightstyle

Well enen at the bathroom taps which are close to the boiler the water is not hot enough IMO, I can keep my hand under the tap and it is not hop enough to be uncomfortable.   I think there is a long run of 22mm pipe down to the kitchen but can't do anything about that as it is all built in.