Is a storage combi boiler the right choice in our situation

[Ikeabudgetdevoltaste]

I can’t find a recent post about storage combi boilers, sorry for the repeat topic.

We live in a Victorian mid-terrace and are about to update it from the millennium. The boiler is a 14 year old Vaillant that is working fantastically but I’d like to change it whilst the bulk of the work is being done if that’s for the best. Reasons to change are that you can’t shower, run the kitchen sink, or any sink, dishwasher, washing machine at the same time. The shower will run cold, the washing machine doesn’t fill properly. Given we’re getting new bathrooms and kitchen I’d like to solve this.

Having a look at old threads, it seems @PigletJohn recommends an unvented storage tank and boiler with immersion heater for back-up. I can’t think of a space to put this. Ideally I’d like to put a boiler in the same space and avoid all the pipe rework too.

For my situation, would a storage combo boiler be the best choice? Or shall I just leave it as it is. Something like the Vaillant ecoTEC plus 940 - 40kW. Its storage volume is 15L. We have a downstairs WC, utility with sink and washing machine, kitchen with sink and plumbed fridge, and upstairs bathroom.

Has anyone bought a storage combi boiler and found it made a difference?

Some people hide things in the loft, but I don't recommend that.

Surely your house is old enough to have had an airing cupboard?

Thanks @PigletJohn. No airing cupboard. Lots of fireplaces.

Really good point, thank you!

@BoilerCodesDOTcoDOTuk if the supply pipe is the issue what can be done?

If the house has an old half inch lead supply pipe, it will not be able to deliver an adequate flow. (It will also probably leak).

Start by asking the water Co to test your drinking water for lead content (this is free, and must be done before you start work). If the pipe is lead ask what schemes they offer for lead replacement. You might get a subsidy or free reconnection.

You do not have to pay their approved contractors to do it. Anyone who knows which end of a spade to hold can dig a trench. If it is not done by an approved contractor they will want to inspect the pipe run before you fill it in. It need not follow the same route as the old pipe.

I would recommend 25mm blue poly, or 32mm if you anticipate several users at the same time, or a hot tub or something, the extra cost of pipe is small, the effort of laying it is the same. Be sure to insist on full-bore valves all the way from meter to boiler. Some people will fit small ones to cut costs but these obstruct flow and are noisy. It is a hundred times harder and more expensive to replace them after the job is finished.

Hmm not sure why @BoilerCodesDOTcoDOTuk post was deleted, it was a perfectly helpful post that wasn’t selling anything.

Thanks for both your replies. I had a look @PigletJohn, anything that can be seen is copper and we’ve had the floor boards pulled up to move the gas meter outside but there is a little lead pipe under the kitchen cabinets coming out of the ground. I called Thames Water today and they said that all comms pipes are plastic in our area, and not to worry the lead pipes are probably so calcified that my water won’t be touching any lead. I’m having a sample done.

So I’ll leave my boiler alone and focus on other ways to improve the water pressure.

I am moving the boiler though so should I replace it? Will efficiency improvements be worth it on a 14 year old Vaillant?

I expect your old boiler is a condensing one. It is fairy modern and Vaillant is a good make. I would not expect a big improvement in efficiency.