Single pipe loop, CH system.

[Will1962]

Hi. Just bought a house,  built in the 50's. Renovating it. Took two rads off in the lounge/dining room, for plastering work. Moved a radiator in a bedroom to an adjacent wall. Noticed that both ends of the radiator connected to the same pipe. Reconnecting the same way. Obviously drained the system for all this. Turned the water back on, but no heat at all. The valliant boiler has a blinking light ( pressure??) I've bled all the connected radiators, twice. Still no heat, not even in the pipes. I did notice a water tank in the loft. Assumed it was disused as the house has a boiler. 

Any advice....anyone. 

 

[Murdoch]

Ask on a plumbers / heating engineers forum maybe

 

[ProDave]

If there is a small header tank that might be for the heating.  It's common for the ballcock to sieze up and not refill the header as it so rarely gets used.

 

[Geoff1946]

A relative of mine had a single pipe system in a flat. It was difficult to balance the radiators whilst getting enough flow for the boiler, but did more or less work. The design is not the reason yours doesn't work now.

Establish basics. Is it a pressurised system, (top up near or on the boiler), or is it open, (ie little header tank in the loft)?    Clearly you've refilled it somehow after draining, so most likely it's still airlocked somewhere. 

Long horizontal pipe runs can be a pain to get the air out. 

Is it a system boiler or a combi?  If the latter, does the hot water work?  If it doesn't then surely a boiler problem.  If its a system boiler are there any zone valves?

Has the air vented from the boiler? - Probably an auto vent on it', perhaps stuck.

Is the pump running? 

 

[Will1962]

Thanks  Dave & Geoff, great input. Its a valliant combi boiler. I've just returned to the house and I'm going to check the hot water. I've checked the boiler already and it has a code f64 showing that wasn't there yesterday. Water pressure in the boiler is ok , but no hot water either. Its going to be a long day.

Or two.

I'm going to have to check the loft and take a look at those tanks.

 

[Will1962]

Ok, I've checked the tanks in the loft. They are both bone dry and physically disconnected from the system. 

 

[Geoff1946]

OK. So its been converted from an open system to a combi.  That fault code googles as being to do with temperature sensors within the boiler.

You just might have confused it if you ran it whilst not circulating water properly, but more likely you are going to need a boiler technician.

I assume you will have powered it off / on again to try to reset the fault register?

From personal experience I recommend a Vaillant tech, or otherwise get recommendations for a local guy. DO NOT go for that large organisation who advertise a lot!

 

[Evans Electric]

DO NOT go for that large organisation who advertise a lot

Ah  Yes   the....   " You need a new boiler Sir "  ....people .  

Was your radiator .."in series"   with the pipe ?    In one end & out the other  or was there two  tees off the same pipe ?