Search results

Mines a fully pumped system installed in 1996. It originally had a heat only boiler but we now have a system boiler installed in 2015. The main pipework is 28mm and the pipework to the radiators is 15mm, i dont know what happens to the pipework under the floor.

My boiler flow and return pipework is 28mm so not unusual.

You must have two motorised valves, the wiring looks like an s plan.

Its a Honeywell valve body, same as mine.

If your friend replaces the Vaillant controls with Hive it will be a big downgrade. Have a look at what Hive can do, it’s not much other than turn the boiler and on and off.

Are you planning on keeping the existing boiler controls and just installing “smart” TRV’s to act like standard TRV’s?

As I understand it from online posts it can be a right pain in the a*** to get DHWP to work with Viessman boilers due to the demand box requirement. There is a good thread on the Buildhub forum.

How well insulated are your rooms? Heating individual rooms can make the heating less efficient as the cost to heat one room is not necessarily cheaper than heating multiple rooms. Unless the unheated rooms are very well insulated they will just suck the warmth from the heated rooms resulting in...

The diverter valve I can understand, I thought the OP was talking about a motorised valve as in a Y plan system.

Flame on a gas hob are normally blue.

What’s the purpose of the 3 port valve, Combi boilers don’t normally have motorised valves at all.

Maybe a silly question but you are turning them clockwise to turn off?

Pipe work not secure somewhere is possible.

There should be a label on the boiler stating the model and GC number.

It’s very likely that you will need not only the heat pump but also a new hot water cylinder, all radiators replacing and pipe work modifications so expect the HP bill to be a lot more than just a gas boiler replacement.

Is it the valve sticking in the valve body or the motor sticking in the valve head? If it’s the valve head then that can be changed without draining the heating circuit.

Ok, got ya. Just turn the thermostat down very low.

You would have to modify the zone valve wiring as well or just disconnect the valve from the wiring centre completely so there is no call for heat.

The only way to do what the OP wants is to replace the CH motorised valve with a normally open valve to give a PDHW setup but without the ability to change flow temps in the boiler.

Any quote needs to be based on the heat loss survey, I'm surprised BG can state the boiler size without having the heat loss figure.