How do you manage to have a decent bath with a modern combi boiler

[theblackradiator]

I have just replaced my 20 odd year old super reliable fantastic back boiler for one of these so called modern wonders (haha) combi boilers. I was advised to due to energy efficiency and running costs and I also struggled to find a gas safe engineer to service old boiler as younger guys now are not trained to service them. so I thought I'd go ahead and modernise and my god how I regret it! so much so I could cry it feels like a total downgrade compared to my old mid 90s backboiler. Running the bath takes a good 20 minutes or more longer, water no where near hot enough for a decent bath as boiler will only heat up to 65 degrees and by the time the bath is filled its going cold. we are a house that absolutely loves and needs baths to help with the aches and pains I suffer from. the central heating seems to work OK but to be honest I think old boiler kept the house consistently warmer and as for running costs I've noticed no difference at all as yet (according to my smart meter readings). no idea of the reason for my long post sorry, I just wanted to vent but if anyone does have any ideas of how to improve my bath water other than boiling the kettle! then any advice welcome. honestly feel I've just totally wasted £3000 to downgrade.

I usually start the Bath with the hot water on full. It’s not broiling hot then but a nice warm ish temperature (warm enough to go in the Bath but hit hit enough fur me).
I tend reduce the flow, which results in higher temperature and finish to fill the Bath like this.
i could not fill the Bath with only the hottest water. I would burn myself going in.

Just okay around with it. A combi boiler means you can have a Bath and someone else a shower afterwards. Much better Imo.

We had the same problem .. new build with a combi boiler ... could never have a really hot bath ... eventually replaced the boiler after a couple of years. Have since moved and have more of a traditional boiler .. even though it's 20 years old now at least we have decent hot baths.

I have 8 radiators in my house 1 of them is only tiny though in the downstairs loo. all the downstairs radiators are brand new fitted with the new boiler. apparently plumber said he said under current regulations he had to fit the smallest kW boiler that my property could manage with. I actually thought the cost was very reasonable for all the work as was a complete back boiler removal all new pipe work, radiators etc and the job took him a few days. I have a 10 year guarantee. those who do not have combis what type of boiler do you have? I honestly didn't do my research and just assumed everyone had a combi these days and it was they way to go. I will try the preheat water setting.

Have had 2 combi's (2 different houses) and rate them! In fact, we have the same boiler as you now.

You do have to use them slightly differently though. When we run the kids bath, we run the hot gap first but not on full, more like a half turn and that's the sweet spot for HOT water for us. On full gives us just warm really. Fills up quick for us so appreciate that doesn't help you- we are in a 3 storey house so it has no problems getting the water up to the top bathroom.
Suspect maybe a pressure issue for you?

We have a system boiler with a pressurised cylinder (Mega Flo). Ours is a new Worcester Bosch. So instead of instant hot water like a combi, you heat the water in the tank and it's then stored there. It can give better water pressure especially if you have several bathrooms or have people running taps and things when you're using bath or shower (and means your heating and hot water can operate at the same time too). I really like it. We had a combi in old house but that was a much smaller house.

I am a bit bamboozled by all these filling bath strategies and tap positions though! I just turn tap full on hot on ours to fill, then add some cold to bring it down to temp at the end.

I must be tired, I read how do I manage a decent conversation with a combi boiler. Thought I was missing out!

Just had a new baxi combi boiler fitted.
It takes ages to get hot water but then fills the bath really well with very hot water.

What I absolutely hate about it is that once you are in the bath for say 10 mins you cannot just turn the hot tap on again as it just pumps out tonnes of cold water for ages again ruining the bath.

Just changing the boiler cost me about £2000, so I think for the work you had done it was a fair price. Remember you are paying for a GasSafe registered heating engineer to use their expertise. And just a reminder that everyone's boiler needs to be serviced annually.First to ensure it will work efficiently, and secondly I'm not sure if the guarantee would be honoured if you didn't.

We have a combi in our holiday home (worcester
bosch) and it fills the bath quickly and its hot enough, you can shower and fill the bath, or run the heating and fill the bath/have a shower.

Is the price just for the boiler, or for all of the work?

The heating and the hot water are 2 separate loops 😂

OP please try turning on the hot tap halfway (not full flow) and come back to tell us if that makes the water come through hotter?

I agree combi boilers do not give reliably hot water. We changed ours in 2012 and choose to keep our hot water tank and replaced our traditional boiler for this very reason, despite the plumber muttering and are really please we did it.

Actually my combi is fine ,the water is reliably hot, and it's the same make as the OPs, I think the issue is more that as the boiler heats water direct from the mains, on a cold day it might not get to quite the same temp as water kept in a tank. The boiler will keep firing up to ensure the water in the tank maintains the correct temp.but clearly the boiler only works when the timer is on.

Ours is a system boiler (I think that's the term). It's still a condensing boiler but we have the hot water cylinder in the airing cupboard. The cylinder is pressurised so hot water is at mains pressure. There's an immersion heater inside the cylinder so if the gas boiler goes faulty, we can heat the water with electricity.

My PIL had this when they switched to a combi. They ended up buying another new (traditional) system.
By contrast we have the biggest combi on the market (at the time) and have no problems pouring a bath etc at all.
Think it might be down to the type you had installed,

Hi, just been reading the thread as I am looking to move from a conventional boiler with cylinder and tank to a Combi boiler.

I understand with a Combi boiler you cannot run a bath and a shower at the same time, however can you have the Central Heating on and run a bath at the same time?

With regards to the bath I am reading, if you want hot water the tap must only be turned 25-50% open to allow the water passing through the boiler to hit the flame - is it at all possible to have a quick hot full bath with a Combi boiler?

Looking at Which website within a video the following is mentioned:
<=9 radiators = 27kw or less boiler
10-15 radiators = 28-34km boiler
15+ radiators = 34kw+ boiler

I live in a semi-detached, 2 bed, 1 bath with 9 radiators and possibly may convert garage making it 10 radiators.

For those that have no problems filling their bath with hot water - what boiler make and model are you using against house size?

thanks.

I have the same boiler. Have a bath every day and have no issues - couple of tips, turn up water to max and when topping up don’t run hot tap on full strength.

For your house size and radiator number I would get a 30KW combi (if you have to have a combi). It's more than sufficient. Don't go for smaller as the hot water throughput won't be enough .

Best makes to go for based on my experience and taking to many heating engineers:

1. Vaillant
2. Worcester Bosch

After that you can go for glow worm who I think are owned by vaillant and then Baxi, or even Majn which is made by Baxi but is more basic.

The price also depends on the warranty.
I would get one with at least 7 or 10 years warranty. You can get cheaper ones with 2 year warranties.

To keep your warranty valid, the boiler has to be serviced every year, within the right time frame or not too early and not too late. I think it's a 60 day window but check.

We have experience with both types of set-up and I have to say I much prefer a system boiler with unvented cylinder to the combi we have in our other property. I find combis a PITA. The water is always cold when you turn on the tap and often doesn't heat up by the time you have finished washing your hands or washing a few things. Taking a bath is also horrible. If you need to top the water up after 15 mins the hot tap just gives cold water for ages ruining the bath.

We have a system boiler and small unvented cylinder providing hot water and heating for a large 2 bed property and I'm so glad I went for a like for like recently instead of switching to a combi. We have a combi in another place and I don't like it although it makes sense as its not used much.

One more thing I learned. Unvented cylinders like Megaflow are REALLY well insulated. They basically lose something like just 2 degree of heat in 24 hours. So we don't worry about heating excess hot water in our tank, it stays boiling hot overnight and we just use it the next day. I love this set up even though it takes a bit more space.

Why are you looking to move from conventional boiler and tank to combi?

Never had a problem with a combi boiler.

I just timed it, our hot water from the tap is warm in 4 seconds and getting too hot to touch in 15 seconds. This is on full blast, non of this making it run at a trickle.

I am pending first quote however the current engineer advised it would be expensive to replace like for like as there would also need to be an upgrade on
new pump , cylinder,, dverter valve and changing pipes.

I actually think it is the pump that is faulty in my current system not the 3 point diverter valve.

I would prefer to keep conventional boiler and my gut instinct is combi is a con having everything integrated.

Glad to hear you have no problems.
Which boiler brand, model and power do you have against how many rooms, bathrooms, showers, radiators?

Our combi in old house was a pain in the arse. But that was due to really poor water pressure. Bath took half an hour to run, showers went cold if you filled the kettle.

new house had old water tank system which we upgraded to a megaflo. It’s brilliant. Bath is super hot and fills in minutes (careful it doesn’t overflow now…) Also house has amazing water pressure. Great showers.

Thank you for your response.

On the Worcester Bosch website I put in the following criteria
Semi 1bath 2bed gas Combi garage side wall
The following 3 Combi boilers are suggested:
Green star 4000 25kw 24kw 10.2l/min 9l/min
Green star 25Si compact 24kw 10.2l/min 8.9l/min
Green star 28cdi compact 24kw 11.4l/min 10l/min

I will look at for the ones nearer 30Kw and also at Vaillant.

I am pending first quote however the current engineer advised it would be expensive to replace like for like as there would also need to be an upgrade on
new pump , cylinder,, dverter valve and changing pipes.

I actually think it is the pump that is faulty in my current system not the 3 point diverter valve.

I would prefer to keep conventional boiler and my gut instinct is combi is a con having everything integrated.

So a Combi can be good if you have the correct Kw power and water pressure against home's demand ?

I do much prefer a tank to be honest, it heated up for 30 minutes in the morning and that would see me through the day with a bath and enough to do the washing up / wash hands.

I am been told it will cost a lot more to have a conventional boiler due to upgrade on
new pump , cylinder, diverter valve and changing pipes.
I think it is the pump that is faulty in my current system.