Do I move to Combi Boiler?

chouglez

chouglez

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I have a real dialemma at hand and need some advice folks.

I currently have a storage talk + pump arrangement so that the pressure is good (not great) in the showers. I am in the middle of loft conversion and was advised to go with a combi boiler maily because the storage tank in the eves does not fit as planned and would be stealing some more space from an already tiny study room in the loft. The plumber has confirmed that via the garden tap the current pressure is 2 bars and 14-16 litres.

My biggest worry is if I go with a combi boiler which is an additonal cost of £2500 would I still get adequate pressure in showers (one existing and one new in the loft) as I do not have an option to attach a pump to a combi boiler setup? :thinking:

Any advice is much appreciated. :thumbs:
 
Don't know much about the shower arrangement, I have an electric one, but 2.5k for a combi seems overpriced to me. Mine was £800 with remote timer & £200 for fitting. Best thing I ever bought, saves on gas and we have instant hot water in seconds.
 
2.5k seems an awful lot, unless there's a lot of pipework that needs doing as well to reroute all your current hot water :thinking::thinking:

I have a combi, and its not up to the job of supplying the hot water to the shower as well as heating, despite the plumber telling us it would be fine. The reality is that the water is fine for the first few minutes of the shower, but towards the end it starts to get cold.

I was quoted £1800 to get it replaced with a boiler that would be able to cope. This is for heating a 5 bed house, bath and 2 showers. Dont know what size house you have which would have a bearing on things i guess.
 
I had a decent quality Vaillant replacement combi boiler fitted in January this year. It cost £2,000 including supply, fit, flush, MagnaClean, VAT, five year warranty etc.. I had three quotes and two were at £2,000 and one was at £2,350. The dearest quote came through with an offer of £300 scrappage shortly afterwards, but it was too little, too late, and I don't like the "double glazing" sales tactics. The job went to the guy with the honest quote and most comprehensive service. I have a friend who is a plumber, and although he is not qualified for gas work any longer he said that £2,000 was about right. An inferior boiler could, I'm sure, be supplied and fitted for less, maybe with a shorter warranty, perhaps no system flush and maybe without a MagnaClean, but I think I got a fair deal.

I can imagine that having to untangle the existing pipework and add in new stuff could easily increase the bill compared to what I paid.

Oh, the previous combi boiler (E.L.M. LeBlanc) survived 22 years and the only repair work required during that time was two new thermocouples.
 
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My combi is in the kitchen, we have a mixer tap in the bathroom that feeds a shower over bath, loads of pressure.
However, it has a tendency to freeze its dump pipe in winter (they should now be internal or lagged and electrically traced to hopefully prevent this, too early to tell as yet), which is a common problem and hasnt been fully addressed. Once that happens the boiler switches off, not good.
I aquired this setup when I bought the house 3 yrs ago, I am investigating putting an electric shower or heated tank arrangement in so I dont end up with no hot water in winter, it can freeze mid-shower of course and cut off all hot water, the Mrs just loves that.
When they work they are brilliant, when they dont they are a nightmare.
I understand also they are very expensive to repair so a maintenance contract is a must.

HTH
Matt
 
chouglez said:
The plumber has confirmed that via the garden tap the current pressure is 2 bars and 14-16 litres.
Click to expand...

Affraid I cannot comment on the bolier but I would urge you to test the water pressure at times of peak demand.

We had very poor pressure to our house, so poor infact that at times our boiler would refuse to light and sometimes you could be in the middle of a shower and the pressure would just drop off to a trickle (cold trickle).

The water supplier came and tested the pressure at 10am on a Friday morning and of course it was OK. I don't recall the figure but the chap seemed to think it was quite OK.

Peak demand for us is weekday mornings 6.30 - 8.00 - had to get up early to get a shower - and pretty much all day Sat and most of Sunday as well.

We had our old lead incoming main replaced and things improved, but a major upgrade of the water mains in our area stopped the problem.

I can still tell the pressure is reduced at peak times but it's not low enough to cause us any more problems.

HTH

David
 
Solved our poor water pressure for the shower with a shower pump. Fitted under the bath it takes no space up. We already had an airing cupboard with a cylinder in it so we fitted a sealed system boiler. No need for tanks in the loft so it freed up loads of room. We also fitted the condenser boiler into the loft on the gable end, making more room in the kitchen where our old flued system used to be.
 
Combi makes a lot of difference to fuel costs and heating efficiency but make sure you get one powerful enough to cope with your needs.
 
2 bar of pressure is adequate enough, and 14-16 litres is not bad for the flow rate. The combi boiler will run a shower quite sufficiently. The moment another tap is turned you will find that the pressure drops at the shower and at the tap that has been turned on. If you are using the shower upstairs in the loft conversion and another shower is turned on you may lose as much as 75 percent of pressure to the upstairs shower. Combi boilers work absolutely fine but you have to know there limits. I would recommend the worcester bosch range of combi boilers. T get tip top pressure at all outlets you would have to go for a system boiler and a megaflo, but as space is a premium this may not be an option. Especially at a cost of 4-5k.
 
Personally I would say that 14-16 litres is on the low side for a decent combi. An entry level model requires 9 l/min for hot water and this would leave just 7 litres for the cold. If the cold tap is opened on the kitchen sink is opened there is a good chance of the hot water running scalding hot.

As a rule of thumb I generally like to see a mains flow rate of twice the stated requirement for the hot water. With this in mind I'd like to see at least 18 l/min for an entry level combi.

There's a lot of dissatisfaction with combis mainly because they are over sold, they are not always suitable for every installation.
 
Combi uses less fuel but it'll still take 20 years to get the cost of installing it back

My boiler is 25 years old, 4 bed detached house, gas bill is £36 a month

I thought about changing to a combi but from what I read they break down a lot so i'm sticking with this one until I have to replace it
 
My first experience of a combi was when I tried to run a bath at a relative's house. It took over an hour, and of course the water in the bath was getting colder as it filled up.

Interesting advice I read from a plumber was instead of getting one big boiler, if you want capacity, get two smaller ones. You have the added great benefit that if one breaks down [apparently a common problem] you still have one working.
 
MisterE said:
Interesting advice I read from a plumber was instead of getting one big boiler, if you want capacity, get two smaller ones. You have the added great benefit that if one breaks down [apparently a common problem] you still have one working.
Click to expand...

what a salesman :D
 
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