Unvented cylinder + boiler

golden_eagle

I am so confused. We are getting 2 new bathrooms installed which will include 2 power showers. We have a good water pressure in the house but will need a new water system put in to cater for both power showers as the tank we have is too small.

We wanted to get Megaflo but it is very expensive. Our heating engineer suggests Telford Tempest unvented cylinder (250l). It's only 2 of us in the house at the moment but we are looking at it long term if we have kids in the future plus we have visitors almost every weekend so more than 1 shower at the same time is a must. The 250l was only a little more expensive so it makes sense.

We also have a fairly old boiler so thought it might make sense to replace it at the same time. The heating eng recommends Remeha Avanta 30s.

My questions are:

- has anyone have experience of Telford Tempest and Remeha Avanta? I have read some unflattering reviews for R.Avanta.
- is what the heating eng proposes best for our circumstances?

thanks for any help.

gas4you

Depends what you mean exactly by 'power shower'.

If you mean a standard thermostatic shower, then that is ok. If you mean an actual power shower, then you can't have that fitted to an unvented system. The shower will work at the pressure/flow from the unvented cylinder.

A lot cheaper alternative for an unvented cylinder is the Main brand. These are the same as the Santon, but with a lot less warranty.

Strangely enough, I visited a customer yesterday with the Telford Tempest. He bought it last year and I fitted it for him. He is very pleased with it.

He also has the Avanta 18S boiler that I fitted.

I fit loads of Avanta boilers and generally they are ok, but I am getting a few warranty calls of late.

Yes, the system he is proposing is good. I would question the size of boiler though. 30Kw is for a damn big house!!

golden_eagle

gas4you wrote: »

Depends what you mean exactly by 'power shower'.

If you mean a standard thermostatic shower, then that is ok. If you mean an actual power shower, then you can't have that fitted to an unvented system. The shower will work at the pressure/flow from the unvented cylinder.

A lot cheaper alternative for an unvented cylinder is the Main brand. These are the same as the Santon, but with a lot less warranty.

Strangely enough, I visited a customer yesterday with the Telford Tempest. He bought it last year and I fitted it for him. He is very pleased with it.

He also has the Avanta 18S boiler that I fitted.

I fit loads of Avanta boilers and generally they are ok, but I am getting a few warranty calls of late.

Yes, the system he is proposing is good. I would question the size of boiler though. 30Kw is for a damn big house!!

thanks for that. Ok, stupid question but what is the difference between the Telford Tempest and Santon/Main?

The size of our house is - 4 bed edwardian bungalow (so very high ceilings) we are having additional radiators put in so that the house is a bit warmer (nightmare to heat at present). Maybe that's why he's recommending such big boiler?

as for what power shower we are getting - well not quite sure of the difference really. About to go shower shopping this morning. Was thinking of Hansgrohe shower - the head is MASSIVE. Can it work on the system he proposes or should i question him?

thanks again

Cardew

Are you sure you really mean a 'power shower'? There seems a lot of confusion about the term.

Some people on MSE even use that term for an electric shower!!! obviously not the OP as the water will be coming from a hot water tank.

A 'power shower' normally refers to a shower where the flow is boosted by an electric pump that switches on when there is demand from the shower. Often a shower cabinet will have other sprays mounted in the wall. They are capable of delivering huge flow rates.

That said the term 'power shower is(confusingly) sometimes used for high pressure showers e.g. venturi shower.

golden_eagle

Cardew wrote: »

Are you sure you really mean a 'power shower'? There seems a lot of confusion about the term.

Some people on MSE even use that term for an electric shower!!! obviously not the OP as the water will be coming from a hot water tank.

A 'power shower' normally refers to a shower where the flow is boosted by an electric pump that switches on when there is demand from the shower. Often a shower cabinet will have other sprays mounted in the wall. They are capable of delivering huge flow rates.

That said the term 'power shower is(confusingly) sometimes used for high pressure showers e.g. venturi shower.

Right, have just checked and we are definitely getting a power shower. No electric pump.

gas4you

golden_eagle wrote: »

thanks for that. Ok, stupid question but what is the difference between the Telford Tempest and Santon/Main?

Not a stupid question at all.

In terms of you using it, nothing at all.

I only mentioned the Main, as they are usually a lot cheaper than any others.

I still tend to think that 30Kw is too big, obviously I havent seen the size of your rooms, but the last 30Kw I fitted was for a listed 3 storey detached house that had 23 radiators over loads of rooms, all that also hadvery high ceilings. It also had a 300 litre Vaillant Unistor unvented cylinder fitted.

If your property is that big, then it should be zoned into at least two zones plus HW, to comply with current regs.

Pincher

golden_eagle wrote: »

Right, have just checked and we are definitely getting a power shower. No electric pump.

Power shower = electric pump to boost pressure, not allowed on mains supply, because you can reduce the water pressure for your neighbours.

Electric shower = Cold water feed is heated electrically by wall mounted unit. You set the temperature by turning the dial.

Get your engineer to measure the mains pressure first: 2 bar, 3 bar?.
Work out the size of pipe from the pavement into your house: 15mm lead pipe, 25mm blue MDPE?

If you have 3 bars or more and 25mm MDPE pipe mains supply, you are laughing. Otherwise it's a bit more complicated to feed the monsoon shower head. It's all do-able.

Split configuration. Keep loft tank and opened vented cylinder. Put a 3 bar pump on the cold and hot water output, and feed only bathroom one. Use a combi boiler to do central heating, heat the open vented cylinder, AND supply hot water to bathroom two and the kitchen.
Bathroom one can have a monsoon shower, because it has a pump., which is allowed because it is not pumping mains supply directly.

Also, bathroom one is using water "stored earlier", so if you have a small mains pipe, it's less of a problem.

golden_eagle

gas4you wrote: »

Not a stupid question at all.

I still tend to think that 30Kw is too big, obviously I havent seen the size of your rooms, but the last 30Kw I fitted was for a listed 3 storey detached house that had 23 radiators over loads of rooms, all that also hadvery high ceilings. It also had a 300 litre Vaillant Unistor unvented cylinder fitted.

thanks again. :beer:just been to a bathroom shop and we may leave a new boiler for another time as with everything else it may be too expensive to do it all this time. OUr heating Eng doesn't think we need a new boiler although our is probably about 8-10 years old but it could do for a bit longer and we can replace it at a later stage. Will query however the size of it as I don't think our house is that massive (although it is detached).

reeac

In my experience boilers last 20 years or so so may be sensible to keep the existing one to see how it goes.