Loft water tanks... why?

[Koldov]

Have to admit my ignorance here...

 

I moved into my current home about 26 years ago, one of the first things I had done immediately was getting a gas combi-boiler installed.

 

The copper immersion tank went (in my 'home owner' naivety I agreed with the plumber that he was 'doing me a favour' removing it for me)...

 

The massive plastic water tank in the loft also went (he didn't want to cut that up and take it for some reason)...

 

Anyway, just to say I have no experience of these things, I just turn on the tap and hot water comes out, I turn on the heating and the radiators get warm... there is nothing I need to think about (apart from the monthly gas bill)...

 

Fast forward 26 years and I've finally bowed to the pressure from the OH to move to a bungalow in a 'nice' rural village!

 

I am now faced with a massive oil tank in the garden linked to a 20 year old oil fired boiler for central heating and a small immersion tank for hot water.

 

 

On one viewing I looked in the loft and was faced with the following...

 

 

 

 

What the hell are these for!!!!

 

Try and ignore that the top one looks like it's held up with shelf brackets attached to a chimney breast...

 

I certainly hope none of these are attached to a tap that I have to drink from...

 

EDIT: Oh and don't mention the fact that one of the chimney breasts has been removed and doesn't appear to be adequately supported (in fact just had some bricks and mortar thrown at it) and has a water tank hanging off it (rather sore point as is much of this ridiculous farce of a house purchase which I won't bore you with)...

Edited September 24, 2024 by Koldov

[Andrew_C]

Header tanks. They provide constant pressure for hot water and heating system. Don't drink or fill cooking water from the hot tap!

 

This is why England has seperate hot and cold taps; to the utter bafflement of Americans. (Our houses are often older than their country)

[mavhc]

https://www.dwi.gov.uk/consumers/learn-more-about-your-water/water-storage-tanks-and-cisterns/

 

Test your taps by seeing if you can hold back the water with your thumb, if yes, it's low press fed from the tanks, if no, high pressure, from the mains

Edited September 24, 2024 by mavhc

[LeMarchand]

EDIT: Oh and don't mention the fact that one of the chimney breasts has been removed and doesn't appear to be adequately supported (in fact just had some bricks and mortar thrown at it) and has a water tank hanging off it (rather sore point as is much of this ridiculous farce of a house purchase which I won't bore you with)...

 

Yet I suspect you paid a pretty sum for a surveyor whose report was full of weasel words to prevent you from suing them for basically doing the housing equivalent of walking around and kicking the tyres.

[Koldov]

Header tanks. They provide constant pressure for hot water and heating system. Don't drink or fill cooking water from the hot tap!

 

This is why England has seperate hot and cold taps; to the utter bafflement of Americans. (Our houses are often older than their country)

 

Both of them?

 

From the link @mavhc supplied I did wonder if one them was to do with the 'hot' and one of them for the 'cold'...?

 

- - - Updated - - -

 

Yet I suspect you paid a pretty sum for a surveyor whose report was full of weasel words to prevent you from suing them for basically doing the housing equivalent of walking around and kicking the tyres.

 

We have a winner for the bonus question!

[Jobos]

The high tank is for hot water and the lower tank for heating.

[Koldov]

There's also a pipe running down from the left of the tank on the chimney that appears to run down into the living room and disappears behind the open fireplace...? Primitive back boiler?

 

EDIT: I didn't even notice until I looked at the pictures just now that on the right hand it appears one of the pipes is held up with rope tied round one of the roof A-frames...

[PotNoodleTech]

The cold water tank is to provide (some) pressure for your taps. the heating tank is to provide expansion room so that if your boiler or tank has a technical issue and overheats your tank doesnt explode killing you and your family. (has happened).

 

Franky the whole lot is totally outdated now. The modern way would be a new tank and a heat pump. The budget way would be a Combi boiler which frankly just does its job day in day out for 10 years for not muchy money. The defining factor for me is do you have solar power? if so = heat pump, if not = combi boiler.

 

Up to you.

[Koldov]

Franky the whole lot is totally outdated now. The modern way would be a new tank and a heat pump. The budget way would be a Combi boiler which frankly just does its job day in day out for 10 years for not muchy money. The defining factor for me is do you have solar power? if so = heat pump, if not = combi boiler.

 

Up to you.

 

Pretty much my thoughts exactly!

 

No, no solar... we did look at heat pump, but honestly so many mixed reviews and this is an old 1950's bungalow with very little done to it in terms of modernisation (old oil tank, old boiler, no cavity wall insulation etc.)...

Edited September 24, 2024 by Koldov

[Koldov]

The high tank is for hot water and the lower tank for heating.

 

So when you say the high tank is for hot water, this feeds into the immersion, or does the immersion feed into it...?

[mavhc]

Step 0 to efficiency is always insulation, no point having an efficiency heating system if it's basically outdoors anyway

[Koldov]

The cold water tank is to provide (some) pressure for your taps. .

 

So do we have a consensus if one of these is for cold water or is one for hot water and the other heating?

[Aprice]

The smaller tank basically acts as an expansion vessel for the boilers heating loop that runs through the cylinder and radiators. It's known as a feed & expansion tank or F&E tank. Recently had to figure out how my system worked, which was quite confusing initially as I have an unvented cylinder but also have a vent pipe

 

There's a surprising amount going on with these, when I looked into it. lots of specific distances, the cold storage tank (usually bigger) has to have a higher level than the F&E tank or the sludge filled F&E tank could back flow into the cold tank!

 

Can't believe anyone would install these over a combi, seems like an awful lot more work!

 

Also the whole cold water tank in the loft has always seemed a bit disgusting to me, thankfully with an unvented cylinder I don't have that. but that big tank is what fills your cylinder up and gives you whatever hot water pressure you have.

[3s-gtech]

Do you only have the immersion heater for hot water, no feed from the boiler to the jacket around the tank?

 

It all looks antique and basic enough that you'd benefit from a complete refresh, along with getting some some insulation in your roof across the joists. IMO, don't have cavity wall insulation fitted - houses of this age can often end up very badly damaged by the resulting damp issues. Air gaps in cavities work very well for insulation.

[Koldov]

I'm not sure really, we haven't moved in yet so I haven't gone in and started doing a thorough investigation. There's a lot of pipework (and quite a few pipes in the immersion cupboard - first picture in OP), but I've no idea where they come from, or where they go to... Edited September 24, 2024 by Koldov

[Rob_D]

So do we have a consensus if one of these is for cold water or is one for hot water and the other heating?

It looks similar to our system where 1 is the expansion tank for the central heating loop and the other is to provide additional head pressure for the hot water (water goes from the tank to the immersion/hot water cylinder where it's heated before going to the taps). In some systems it's also used to feed the upstairs (bathroom) cold taps.

 

[Edit: Here's a diagram that makes it all clear as mud]

https://www.schoolphysics.co.uk/age11-14/Heat%20energy/Transfer%20of%20heat%20energy/text/Hot_water_system/index.html

Edited September 24, 2024 by Rob_D

[Aprice]

So do we have a consensus if one of these is for cold water or is one for hot water and the other heating?

 

Yep, little tank keeps the heating loop that heats the Radiators and Hot water cylinder coil filled, and allows for said water to expand when heated.

 

Big tank fills the water in the hot water cylinder, and provides pressure for the hot water. if you open a hot tap it will be water that was in big tank that comes out. Lovely!

[jmak]

Yep, little tank keeps the heating loop that heats the Radiators and Hot water cylinder coil filled, and allows for said water to expand when heated.

 

Big tank fills the water in the hot water cylinder, and provides pressure for the hot water. if you open a hot tap it will be water that was in big tank that comes out. Lovely!

Until we had it replaced with a sealed system and ASHP, that's what was in our loft. Without seeing the pipe runs, I can't be certain this would be true for this installation system, but....

 

That tank also fed the cold taps other than the kitchen sink, which was the only drinking water supply in the house. So that's what you brush your teeth with [emoji16][emoji1785]

[jmak]

Step 0 to efficiency is always insulation, no point having an efficiency heating system if it's basically outdoors anyway

I'd slightly disagree here:

 

Heat demand for the house is the same whatever the heat source. So surely it makes sense from an efficiency point of view to produce your heat.... efficiently.

 

The only advantage of insulating first is if it would allow you to have a smaller (cheaper) ASHP.

 

I'd assume that if there's oil fired heating in a rural area, then there's no mains gas. Looking at the state of the plumbing, you're looking at replacing pipework and radiators anyway and probably the oil tank. Get comparison quotes - I think you'll find an ASHP looks competitive.

 

Running cost comparisons are different from gas fired too. We definitely spend less on electricity than we used to on oil and we have solid walls with no insulation.

[robyholmes]

Consider a Air to Air heat pump too. Or Aircon as a lot of people call it but it heats just as well as it cools. Cheaper to fit although you don't get grants for it. Cheap to run, pretty easy to install if you have outside walls to put it on. And in summer you can have air con too!

 

Being a whole new system it also means you can fit it while still having the old system in place. As we've done. As we decorate rooms we'll take the rads out.

 

PS as @jmak said above. A heat pump will save you more money compared to a boiler in a less insolated building. As heat loss is the same, so both have to replace the heat lost. Insolation will of course save you money, but the 'Heat pumps only work in modern well insolated homes' is a complete myth.

Edited September 24, 2024 by robyholmes

[mavhc]

Insulation is usually waaaaay cheaper for the same efficiency gains, and right sizing your heat pump is important, so buying one that's good for a house that needs twice as much heating and then adding insulation afterwards is bad in multiple ways, costs more, works worse, and you'll probably be replacing radiators for larger ones for no reason

[PotNoodleTech]

I'd slightly disagree here:

 

Heat demand for the house is the same whatever the heat source. So surely it makes sense from an efficiency point of view to produce your heat.... efficiently.

 

 

Mav is right - insulate as much as you can first and then you know what you are dealing with and can size your system appropirately. Most people dont realise how much of a difference it makes e.g. i have not had my heating on yet but I talk to many that are grumbling that they have been burning that $$gas$$

Edited September 25, 2024 by PotNoodleTech

[dhicks]

Or Aircon as a lot of people call it but it heats just as well as it cools.

 

When heating, does it tend to dry the air, as air conditioners do? I live in a very well-insulated flat, the only heating we use is a 1KW fan heater for warming feet up in particularly cold weather. In colder weather we do need to run a dehumidifier to take the moisture out of the air. I wondering if we had a modern air-sourced heat pump / air conditioner it would both do a bit of heating and dry the air?

[PotNoodleTech]

An air conditioner - air to air will dry the air in the house if you want it to so that will be a big benefit if you have a damp house. A water heat pump won't as the unit is generally outside

[jmak]

Loads of variables:

 

Loft insulation - cheap, buy as much as you can

 

Windows - if you're replacing anyway, incremental cost is worth it. Upgrading will take many years to recover cost.

 

Solid walls - if your children inherit your house and continue living in it, they might benefit. It takes decades to recover the cost.

 

Cavity walls - much shorter payback than solid walls and less disruptive, but still quite expensive. I'm still slightly dubious about insulating walls on buildings that weren't designed for it. Dew points and ventilation need to be very carefully considered.

 

Heating system replacement - if you have an "efficient" fossil fuelled system, spend money on insulation. If you're replacing your system anyway, go for a heat pump (ASHP, GSHP, air-to-air). Running costs won't be any higher if the system is well designed - and should be cheaper than oil. If you have modern radiators and plumbing, they probably will only need minimal upgrades, even without additional insulation. If they're old and awful like ours were, the incremental cost is minor.

 

If you're considering CO2 output, replacing the heating system wins. For our solid walled house, we were advised the best we could do would be to improve heat loss by 30%. But that was by a surveyor who didn't look in the loft to find out that we had a decent amount of insulation already. By replacing oil fired with ASHP, we cut energy use by a factor of 4 (SCoP of 4.1 over two years), so that's 75% reduction straight away. On current grid mix (I went with a conservative 40% renewables) that works out as an 85% reduction in CO2 output for our heating system compared to the existing (broken at the time) installation. Or put another way, carrying out all of the recommended improvements would still use 2.8 times as much energy as the system we installed with no additional insulation and produce 4.7 times as much CO2.

 

The cost is very specific to the property, but in our case (Victorian house with high surface area to floor space ratio) the cost of the wall insulation would have been twice what we spent on an ASHP and replacing all the plumbing and radiators, before taking account of the 50% grant.

 

Most annoying thing is our house might become unmortgageable due to EPC rating, despite having similar running costs to a house built earlier this century and using three times as much energy/producing six times as much CO2

 

Edit: You need to factor in how much extra a heat pump installation would cost compared to a straight swap, but the £7.5k grant should help a lot with that.

Edited September 25, 2024 by jmak