Dual heating system questions

CillDaraLily82

I have an oil central heating system along with a stove with a back boiler. The oil boiler needs replacing due to a leak and erosion but is currently still working. The house is a dormer bungalow but upstairs is not completed. I am planning on completing upstairs in about 18 months adding 5 radiators so the boiler and system will have to be upgraded then anyway. I am hoping the current boiler can last this long but the plumber says you just don't know and could go anytime.

If the boiler were to pack in, would I still be able to use my stove and back boiler to heat the house or is it all part of the same system and would cause problems?

A separate question is am I able to light my stove without using the back boiler? I know I can set the thermostat high so that the pump doesn't kick in and circulate to the rads but the fire still seems to heat the water. I am asking this because of the rumour about freezing temperatures on the way. If we get a bad winter and my tank and pipes were to freeze as they did before, can I light my stove without fear of bursting pipes?
Thanks!

Wearb

CillDaraLily82 wrote: »

I have an oil central heating system along with a stove with a back boiler. The oil boiler needs replacing due to a leak and erosion but is currently still working. The house is a dormer bungalow but upstairs is not completed. I am planning on completing upstairs in about 18 months adding 5 radiators so the boiler and system will have to be upgraded then anyway. I am hoping the current boiler can last this long but the plumber says you just don't know and could go anytime.

If the boiler were to pack in, would I still be able to use my stove and back boiler to heat the house or is it all part of the same system and would cause problems?

A separate question is am I able to light my stove without using the back boiler? I know I can set the thermostat high so that the pump doesn't kick in and circulate to the rads but the fire still seems to heat the water. I am asking this because of the rumour about freezing temperatures on the way. If we get a bad winter and my tank and pipes were to freeze as they did before, can I light my stove without fear of bursting pipes?
Thanks!

Don't set the stove stat so high that it causes the stove to boil.

Very difficult to take a chance on answering those questions without seeing how the system is plumbed. If it is plumbed properly it should take very little to isolate the upcoming leak in the oil boiler.
Where is the corrosion on the oil boiler? If the cause has been eliminated, it may last for a while still. How old is it?

CillDaraLily82

It's 10 or 11 years old. It's the original boiler in the house. Plumber has fixed the leak. It could be seen as soon as the casing was opened and the damage it has done all down the left side. It's working fine so I'm hopeful it will last. I'd just like to know more about how the dual system works. They don't seem to be independent of each other so if one breaks are both systems affected?

Wearb

CillDaraLily82 wrote: »

It's 10 or 11 years old. It's the original boiler in the house. Plumber has fixed the leak. It could be seen as soon as the casing was opened and the damage it has done all down the left side. It's working fine so I'm hopeful it will last. I'd just like to know more about how the dual system works. They don't seem to be independent of each other so if one breaks are both systems affected?

Ask your plumber if you could isolate your oil boiler in the event that it started leaking again.
It is too dangerous for me to give you any other advice where a solid fuel boiler is involved.
Why did it leak after such a relatively short period? Did he weld the leak?

CillDaraLily82

I don't know why it leaked. He didn't weld it. Put a new nozzle on a part of it. Thanks anyway. I'll have to get someone to look at the system.

Wearb

CillDaraLily82 wrote: »

I don't know why it leaked. He didn't weld it. Put a new nozzle on a part of it. Thanks anyway. I'll have to get someone to look at the system.

Considering he is expecting you to agree to such a big job, I would expect that he would have given you a better explanation for the need of it.

sky6

As Wearb has said get your plumber to explain the layout. Ask him how are the two systems integrated, are there any Motorized valves or even lever valves on the system.
If your Boiler does go wallop it shouldn't be a big job for any plumber to take it out of the system and leave you with just the Stove/ Boiler, until your ready to get a new one.
on the stove boiler, it's not a good idea to light a fire if you suspect the pipes are frozen, It's actually very dangerous. Especially if your allowing the Water in the boiler to boil. What if the expansion was also frozen.?
How far from the stove is the expansion pipe.? Where are the pipes freezing.?
Is the boiler and pipework in a Garage.
As wearb said get you plumber to answer all of these questions and more.

CillDaraLily82

Common sense told me not to light the fire when the pipes were frozen. I also don't allow it to boil. I was just saying turning up the thermostat seems to be the only way to stop it heating the rads. My question was could the stove ever be used just as a fire without using the back boiler and it seems not. During 2010, both the water tank and central heating tank in the attic froze. Unfortunately until upstairs is completed, the attic is just an open space about 700sq ft with no heating and the minimum insulation. We've insulated the tanks as best we can so hopefully it won't happen again. I'm really just asking what if questions.

The plumber came to service the boiler and fix the leak. I would be getting other opinions and quotes before I replaced the boiler. I was just hoping to get some answers here before calling another plumber out.

The system is set up strangely. I bought the house like this and a few people have commented on it. The oil boiler pump is in the hot press with the stove pump and they are connected with pipes. During the months of inactivity, the stove pump tends to get stuck and has to be loosened with a screwdriver. While it is stuck, the oil system works fine. When it is loosened, both pumps kick in when the oil is on but then the oil pump might cut out after a couple hours and the boiler will knock itself off. Adjusting the thermostat inside the oil boiler casing will sometimes allow it to come back on. The plumber said if he were to put in a new boiler he would rearrange things, putting the oil pump beside the boiler instead of in the hot press.

Again, this would all be sorted out in about 18 months anyway but I'm just asking what if questions. I thought there might be general answers but it seems the system has to be seen first. Thanks for your help anyway!

Wearb

I have seen infra red lamps wired to a frost stat in some attics, to stop water freezing. I have no idea if this is strictly allowed and if done it would need to be well secured and be positioned so as not to cause a fire. Obviously, during a power cut this wouldn't work.
Some modern attics are so well insulated nowadays that its surprising that there are not more freeze-ups during heavy frost.

CillDaraLily82

That confused me a little! Are you saying an attic can be insulated too well so that it will freeze up during frost?

Wearb

CillDaraLily82 wrote: »

That confused me a little! Are you saying an attic can be insulated too well so that it will freeze up during frost?

No I am not saying that, but the amount of insulation used now needs to be taken into account when running pipes etc in well insulated attics.

CillDaraLily82

Ok, I'll look into that more when I'm completing the attic.

Smkopite

Hi just wondering has anyone ever put in a dual heating system and put a seperate tank in for the stove

Smkopite

I keep a thermostat beside the tank in the attic and use the lights up there to keep it from freezing also leave attic door open during freeze it allows warm air to enter attic

Smkopite

How hot will stove heat rads and which is the best fuel for doing so

sky6

Smkopite wrote: »

How hot will stove heat rads and which is the best fuel for doing so

That depends on too many variables. How many Rads ? size of Rads. Size of Boiler stove.
But the simple answer is so hot that you shouldn't be able to hold your hand on them if the system is sized and fitted correctly.