Kettle v combi boiler

A combiboiler is a combination of a central heating boiler and and water heater. When it is heating water for washing that is all it is doing heating hotwater. The central heating is not running as well. In fact it can only do one or the other, not both together, so the amount of gas it uses will presumable the equivalent of heating a kettle on the gas hob.

Remember a unit of electricity is much more expensive than an equivalent unit of gas, so I suggest that heating the water with gas, whether on the hob or the water heater in the boiler casing should work out cheaper.

62granny, ok you are heating pipework unecessarily as there is a long run from the boiler. I would be inclined to use the kettle in that case. There is no longer a big difference between gas and electricity cost and your long pipework makes the combi to kitchen inefficient as in wasted heat, whereas a kettle is very efficient.. I would try and get a smart meter in your case. I don`t have one, don`t want one but for many they are a good thing

We live in a bungalow and the boiler is in the attic, so takes some time to reach our kitchen, I rarely have to rinse plates before washing them, as I wash up straight after the meal is finished and plates are scraped into the food recycling of anything that might be left. We both wash or hands in cold water as it comes out of the tap same when I clean the bathroom, it is rarely ice cold so is fine. We obviously don't have a smart meter otherwise I could check the cost.

Yes combi boiler which seems to take forever before it gets hot, unless the heating is actually on.

When we used to have the luxury of hot water, we’d run the cold water that came out first into two 2 litre milk cartons and use those to fill up the toilet cistern.

I don't have facts and figures but I have read that it costs less to use a dishwasher once a day, or every other day maybe, than to run the tap for a hot water hand wash several times a day.

Our gas meter is stuck so we have not been able to submit a reading for 3 months.
The gas company have cancelled the appointment to come twice now, this has meant they send us £30 compensation for each missed and we are not paying for our gas!
I feel so lucky we can bask in free warmth!

My boiler is 2 rooms away from the kitchen and the I’ve heard the boiler fire up ages before any hot water arrives from the tap. It also must heat all the pipes on the way. I’ve been boiling the kettle to make tea and coffee and use the remains for washing up with detergent and cold water added. I thought it made sense so I’ll wait and continue to read this thread.

I’d experiment but unfortunately we can’t have a smart meter as the outside piping and cabling are too out of date to connect up, according to the people who came to fit the smart meter.

62granny, how far is your sink tap from your combi boiler?

Cold water, washing up liquid, a good scrub and air drying are fine for washing up. There’s no need for hot water, although it is more comfortable to use it.
The same applies to washing of hands if you use soap and the correct technique.

My combi boiler is two rooms away from the kitchen. Maybe that and the length of pipe work influences the time it takes for hot water to reach my kitchen tap. Smart meters, like Smarties, have the answer.

I have a combi boiler right next to the kitchen sink and don’t have to run the water for that long before it gets hot - and surely even if you do have to run it for a bit, it mixes with the hot water to make it hand hot for the dishes. I have a smart meter and I’ve watched it rocket up whenever I boil the kettle, so my guess is that the boiler is cheaper.

Yes PaperMonster. Our old boiler was costing us a fortune and wasn’t efficient.

We don’t have a combo boiler but is a bloomin great big boiler an immersion heater? A couple of years ago we turned it off unless we need a bath and put it on boost for a couple of hours as it was much cheaper to heat the kettle to wash up a couple of times a day. If you have a smart meter, can you calculate it from the display unit?

The OP asks about a combi boiler so presumably no longer has an immersion heater GSM. Her situation is not quite the same as yours.
Aware that the tumble dryer likes to guzzle kWh and with rising prices in mind I decided to compare the cost of my electric oven , hob and microwave. For this I turned to various sites including the Energy Saving Trust. Whilst the EST does not feature an immersion heater, it does indicate that an electric shower of 7,000 to 10,500 watts costs 125% to 350% that of an electric kettle of 3,000 watts - easily evident. (Another site stated that water heated for a shower by electricity is doubled when heated by gas and doubled again when heated by an immersion heater. This is not a dig at you GSM but an exploration of cost.) A smart meter as I suggested will indicate the actual cost of gas to heat water.
Some people collect the initial through put of shower water and use it elsewhere. Others rinse prior to washing with the heating water in the kitchen. In either case it is not necessary to waste it.
The implied cost of a boiling water tap (not on EST) and your thoughts on it are most welcome. Every day’s a school day on GN.

I have found that if you wait and turn the hot tap on when the pump for heating is working the water runs hot pretty quickly! I now wait to wash up until the heating kicks in.

I really don't understand. Surely you want fairly hot water to come out of the tap pretty quickly to have a shower/bath, wash your hands, clean the kitchen and bathroom? Why is the washing up different? If you have to run the tap for a while to get sufficiently hot water then you're wasting a lot and that would show up in your water bills if your supply is metered. The water from our hot tap, heated by the immersion heater, is quickly hot enough for all these things.
We only boil the kettle for hot drinks or for cooking green veg or pasta. We inherited a boiling water tap but disconnected it as it costs a huge amount to have a constant supply of rarely needed boiling water.

I read your post to mean running the combi boiler until you have enough hot water to fill a medium size washing up bowl versus boiling a kettle.
You can measure how much gas and electricity you’re using with a smart meter. The energysavingtrust.org recommends smart meters and is a really useful site.
The other element is the volume of water used - I’m assuming you have to let the water flow until it has been heated sufficiently by the boiler. If you boiled a kettle, you’d still rinse items with tap water before washing. Is the volume of water needed to rinse the same as the volume coming through the tap before the water is hot enough?
Once you’ve gauged the water usage, the smart meter should give you your answer. I hope this helps.

I have often wondered this myself, because it takes about a washing up bowl full of cold before the tap runs hot.

Am I right in assuming the hot water in the tap is actually heated by the Combiboiler anyway?

I would have thought it would be cheaper to use the hot water from the tap.

Why do you need boiling water? I assume you get reasonably hot water from your hot tap?