CH not circulating... Now what?!

[Freezing]

Would love some help!

We bought this house last year. Boiler is an Ideal Classic LXFF, probably 12/15 years old. Very old radiators (with the two pipes going up from the floor, into one pipe to the centre of the radiator).

Last year the boiler stopped working but a new pump seemed to fix it. This summer, it heated the DHW fine with the CH thermostat set to zero. (We don't have dual controls, just one timer that seems to run both.) But when we set the thermostat to 20 degrees on Sunday to put the heating on for the winter, the boiler starting running for just 10 seconds then switching off.

Two plumbers came over, both said it's probably a circulation issue. Sludge, maybe. The first one said a new heat exchanger MIGHT fix it, or a power flush, or capping/replacing pipes. He added that our old radiators might not withstand a power flush and that the valves either side of the new pump were corroded and might not last through a flush. (???). The second plumber just suggested a flush.

The boiler now doesn't light at all. ??

We are using the immersion for DHW but obviously can't afford to do that for long. (45p an hour to heat a 120L tank - is that right?) We have 2 kids in the house and no heating at all. And no money. :-(

questions:

1. How can we tell it's blocked pipes or sludge? I read about draining water off but it sounded best to do that from a hot system, and ours has been cold for 5 days now.
2. Can we attempt a DIY flush? Husband is quite handy, but obviously we don't want to make anything worse!
3. Would adding chemicals to the system loosen a blockage..?
4. What should we do now? We have £500 of home-insurance emergency cover...
5. Should we get a 3rd opinion? Nobody seems to know why the boiler just won't stay lit.

help please! Thanks in advance.

 

[joni os]

If there is water in F&E tank suspect blockage where fill pipe connects to system. Confirm with magnet. System will have been starved of water and pump run dry, hence failure of previous pump. Your new pump is not circulating due to lack of water and boiler has overheated triggering safety cut out. Confirm by reset cut out, button right side of control block. If boiler starts then turn off and call plumber to clear blockage. If boiler fails to start, call heating engineer, GAS SAFE.

 

[jtsplumbing]

Unfortunately you have taken on a old system, pipes going into centre of radiator are Proberly 10mm micro-bore , you could try a system cleaner but it wont be a 5min fix , takes time to get through system, but no guarantee that it will work, what needs to be done is going to be expensive, worst case could mean re-piping the system and replacing radiators.

 

[Freezing]

Hello! Me again. I think it'll have to be new pipe work. We had the pump replaced after three plumbers told us that'd do it (£250), but it didn't help at all.

The plumber seemed really nice. He's said a power flush (£400) might work or, failing that, all new pipes upstairs (£700-800). He said there's a blockage somewhere. Doesn't know where.

Is there anything we can try ourselves? Thanks.

Thanks for the posts already; I didn't understand the top one! Should there not be water in the f&e tank normally?

Thank you ***

 

[jtsplumbing]

Yes should be water in small tank in loft, if not give ball valve a shake up & down Proberly just stuck, £250 for a pump ? you are having a laugh, Do you live in Knightsbridge ??
Power flush MIGHT WORK !! if its micro bore pipe it wont ! 1st check tank in loft system could be low on water !!

 

[acecharly]

Would definately recommend a bottle system cleaner as a first course of action pricewise but as said may take some time to work.

 

[joni os]

Clarification: As JTS says, make sure water in F&E tank. Blockage will be between outlet of F&E tank and Pump. This will be 15mm pipe from tank joining 22mm or larger before pump.
Blockage most likely at or near Tee piece where 15mm joins. Copper pipe is not magnetic but material causing blockage will be. Any magnet, Fridge magnet will do, can be held against pipe in various locations. If it sticks in one location that is where your blockage is.

 

[diamondgas]

Simple blockage check is done with pipe stats! Lots of possible reasons for the symptoms you talk about... With the limited info you've given there's little chance of getting to the bottom of your issue! If it's serious blockage caused by pumping over then a poweflush may struggle to resolve it!! Honestly it all depends on how your pipes are configured as to what the best approach would be.....! Sorry for not being much help ... 🙂

 

[joni os]

Pipe stats great on working system but in this case boiler cuts out after 10 secs. indicating problem more fundamental. Also system cleaner needs circulation in system. If micro bore, remove rads. and flush individually.

 

[Freezing]

You're all being so helpful -- I really appreciate it. I'm sorry if I'm giving limited information, but I understand so little about plumbing, I don't know what info to give! 🙂

Will definitely try the magnet test. I've been reading about this for the past 2 weeks -- am I right in thinking I should try the magnet on the "H" piece of pipe..? Some big connecting piece of pipe where 3 pipes meet? (Do you know what I mean??) where would we find that - under the hot-water/immersion tank?

We are going to try to flush out the rads manually on Thursday.

What's micro bore? What are pipe stats?

Thanks again, really appreciate all this. Xx

 

[Freezing]

Oh, did I mention that the plumber says we've got a single-pipe system? We didn't know that.

 

[Best]

Microbore is the small bore pipes on some systems used to do radiators pipes only. They have to tee off from, or using a manifold (a multi connection point) the large pipes of flow & return.
Usually Microbore is 8mm or 10mm and is a soft copper that comes in a roll when new.
Frankly it's not great as can't do long runs and only does one radiator, but a complete pain if dirt gets into it.
Sounds like you have a blockage on some of the large pipes or a blockage on the feed pipe from tank. You could try a magnet on the tee area where the feed pipe joins into the return off the cylinder in airing cupboard

 

[Best]

Oh, did I mention that the plumber says we've got a single-pipe system? We didn't know that.

Bad news! Better with it all replaced with a brand new 2 pipe system if you can afford it.
A blockage on that would stop it all working.
There is nothing to cure an old badly designed and installed, full of magnetite heating system better than ripping it all out and taking it away for scrap.

 

[joni os]

The comment regarding your central heating pipework, single pipe, microbore etc. is relevant to a long term upgrade but does not explain why your hot water cannot be heated from the boiler. The pipework that heats your domestic hot water cylinder is separate pipework and will not be microbore. Your predicament screams out that you have a blockage in the cold feed. Loosen a nut on the central heating pump and ease pipe away. Water should spray from joint as if from bathroom tap. In your case I am confident it will be a trickle or none at all.
Have towel handy to protect electrics. ( This assumes pump is located in airing cuboard and is higher than radiators).

 

[jtsplumbing]

Think you would be better requesting some one from this site visits your home from whom you would get an honest answer, as B4 your problems cant be sorted from guessing, and you have limited knowledge of what is going on, start at basic point, is water in small tank ? is water getting into system, don't keep messing around just call someone in to check these basic things first instead of paying out for new pumps etc. any plumber that knows what he/she is doing would take less than 1hr to do basic checks, Put a request on looking for a plumber on this site, if you had called the right person in the first place this could have been sorted 2 weeks ago

 

[Freezing]

Thank you all. We are still cold! 🙂

*joni os* -- I just showed your last post to my husband. What do we do if the pump is LOWER than the radiators? Our boiler is on the wall, just above the floor, in the kitchen. Then there's a pipe that goes up about 5' to the ceiling in the kitchen, which is where the pump is located.

 

[Freezing]

*jts plumbing* -- we have called lots of plumbers.

 

[joni os]

With pump lower than rads. water could drain from rads or coil, even though system not filling from F&E tank so cracking nut on pump would not be conclusive. You still need to find where 15mm pipe from F&E tank joins your 22mm pipework and test with magnet.

 

[jtsplumbing]

*jts plumbing* -- we have called lots of plumbers.

cant understand why no one will call out to you ! have you put a request on this site ? what is your location ?

 

[Freezing]

Sorry, that was misleading of me. We haven't called out for a plumber from here, no. That's a good idea! We've just called out 5 plumbers from the local directory of recommended tradespeople. It's usually a very reliable source of trustworthy people.

We had another plumber round last night, who said we might just need a power flush BUT he wouldn't risk doing that on a one-pipe system. He wouldn't touch it, unless we want him to rip it all out and re-pipe, new rads, etc. It's getting to that stage, I think.

In desperation, we have tried the following:

* Gone round with magnets on EVERY pipe we can find, in house, loft, everywhere. There might have been a tiny bit of attraction in 2 places, but the plumber said it wasn't much.

* Tried Screwfix system-cleaner in the F&E tank last week.

* Today, husband drained off the whole system. The water was a dirty, murky blacky-grey. Then we took off the rad in the downstairs loo and rinsed it out. The water from that was BLACK, like jet-black ink. We only did one rad as the mess it made when it came off - black water just went WHOOSH all over the floor, despite the system being empty (we thought) - was UNREAL and every other room is carpeted.

* Poured a bottle of Sentinel X400 into the F&E tank, and refilled the system. Now I guess we bleed every rad, and wait a few days?

After this, I think we'll get quotes to install a new system. Do you think?

 

[Freezing]

We are in Berkshire, near Bracknell/Reading.

 

[Freezing]

Should we try sluicing out all the radiators? Is there a way to stop an explosion of inky black liquid when we do? The water is like black paint.

 

[Freezing]

Why was the rad water so SO much dirtier than the water from the system?

 

[PlumbBobBob]

the rad water is so much dirtier because sludge will have collected along the bottom of the rad, which is dislodged when flushing through. when you take a rad off close off both rad valves just incase the system is not completely empty.

 

[jtsplumbing]

We are in Berkshire, near Bracknell/Reading.

How strange is that ! I lived in Bracknell for 20 years, just off Binfield road now moved back to west country, 400 cleaner will need more than a few days, I would have used Fernox F5 heavy duty cleaner, will send you a private message with a couple of local plumbers near to you.

 

[Freezing]

Ha ha! We are just off Binfield Road! Thanks so much for your message. ***

 

[Freezing]

Annoying we used the wrong cleaning stuff. This system is doomed! Arghhhhhh!!!