Replacement Boiler Query

natalie_1982

The house we moved in to 5 years ago has a combi boiler installed but the water pressure is so low that our electric shower is no more than a dribble and running a bath takes about half an hour. The boiler is now 11 years old and I am considering replacing it with a regular boiler but this would require getting a new water tank and everything installed. I have two people coming out next week for a quote/advice, but was wondering in the mean time how much I would be looking at in both terms of cost and also the amount of work that would need to be undertaken. There is not currently a water tank in the loft. Thanks for your help.

macman

Can the water pressure be improved? Has it been properly measured and the flow checked?

natalie_1982

I don't think it can - Thames Water have been out previously to check for leaks, etc but it appears to be a common problem in the area rather than just our home.

WestonDave

One point - changing the boiler won't improve the flow through an electric instant heat shower if that is what you are referring to as an electric shower.

Combi's will tend to be relatively slow running a bath because they are having to heat the water as it runs through it so if you want really hot water it needs a relatively low flow to get it that hot in the time the water is passing through. Changing to a system boiler could help this by giving water more time to heat within the tank, but it might also be worth asking an engineer about a more powerful combi. Do you know what model it is?

Regarding the shower, I'd guess that at this time of year the "dribble" is more related to a lowish power shower trying to heat cold ground water. These work on a similar principle - the heater is on full blast all the time and the temperature is regulated by the water flow - fast flow = cool shower (as little chance to heat it up), low flow = hotter shower as more time in the heating chamber. Again posting the make and model would help advise. It may be that changing this for a more powerful model would mean water can be heated faster and so have a more generous flow (although even the best electric showers tend to have weak flow).

natalie_1982

WestonDave wrote: »

One point - changing the boiler won't improve the flow through an electric instant heat shower if that is what you are referring to as an electric shower.

Combi's will tend to be relatively slow running a bath because they are having to heat the water as it runs through it so if you want really hot water it needs a relatively low flow to get it that hot in the time the water is passing through. Changing to a system boiler could help this by giving water more time to heat within the tank, but it might also be worth asking an engineer about a more powerful combi. Do you know what model it is?

Regarding the shower, I'd guess that at this time of year the "dribble" is more related to a lowish power shower trying to heat cold ground water. These work on a similar principle - the heater is on full blast all the time and the temperature is regulated by the water flow - fast flow = cool shower (as little chance to heat it up), low flow = hotter shower as more time in the heating chamber. Again posting the make and model would help advise. It may be that changing this for a more powerful model would mean water can be heated faster and so have a more generous flow (although even the best electric showers tend to have weak flow).

Thanks I guess I should have said but I was thinking that if I got a regular boiler installed then I could get a power shower installed. I do not have the models of either the boiler or shower to hand but can get them. When we had the shower put in it was the most powerful we could get with our boiler. The water flow has always been very slow athough appears to be a little faster from the kitchen tap than the bathroom ones.

macman

The shower you have at present has nothing to do with the boiler. An electric shower is fed direct from the rising main, and the water is heated in the shower unit.
Your electric shower would function the same with any boiler, or indeed without one at all.

rogerblack

macman wrote: »

The shower you have at present has nothing to do with the boiler. An electric shower is fed direct from the rising main, and the water is heated in the shower unit.
Your electric shower would function the same with any boiler, or indeed without one at all.

The OP is referring to getting a non-combi boiler fitted, along with a hot/cold water tank.
This would allow greater flow, simply as you can empty the tank as fast as you want.
Fitting pumps to a very slow flowing incoming main is a really bad idea, as it causes negative pressure, which may suck stuff into the pipe, as well as being not permitted under regulations IIRC.

A conventional water tank is one of the few solutions, though has issues of its own.

macman

rogerblack wrote: »

The OP is referring to getting a non-combi boiler fitted, along with a hot/cold water tank.
This would allow greater flow, simply as you can empty the tank as fast as you want.
Fitting pumps to a very slow flowing incoming main is a really bad idea, as it causes negative pressure, which may suck stuff into the pipe, as well as being not permitted under regulations IIRC.

A conventional water tank is one of the few solutions, though has issues of its own.

I'm aware of the OP's current install. Where did I suggest fitting a pumped power shower to the current set up?
I was simply pointing out that the shower issue is not caused by any boiler defect.

natalie_1982

macman wrote: »

I'm aware of the OP's current install. Where did I suggest fitting a pumped power shower to the current set up?
I was simply pointing out that the shower issue is not caused by any boiler defect.

Thanks but I know there is no link between the low water pressure and boiler, it is more to enable me to get a regular boiler and water tank installed so I could get a new shower installed.

When we had the shower put in they said it was as powerful as it was going to be and it would be dangerous to install a booster.