New Valiant 835 Boiler but radiators now not working

I understand your frustration with your new Valiant 835 boiler and the radiators not working properly. It's definitely understandable to explore options like a circulatory pump or boiler settings before considering major pipework changes. Here's my analysis based on the information you provided: **Current Situation:** * New Valiant 835 boiler installed. * Previously working radiators (9 total) malfunctioning after flush and TRV replacements. * Downstairs: 3 rads working, 1 lukewarm. * Middle floor: All rads working. * Top floor: 1 rad working warmly, the other not. * System balanced, cold rads lockshielded open, thermostats high. * Radiators bled, constant water flow confirms no air. **Possible Causes:** 1. **Pipework Blockage:** Although unlikely if only old radiators were replaced, hidden blockages in specific sections of the pipework could still be restricting flow. 2. **Faulty TRVs:** Even new TRVs can be faulty, particularly if there's a batch issue. Try swapping some around to see if the problem follows. 3. **Pump Issue:** The current pump might not be strong enough for the new boiler and increased resistance from additional pipework. A circulatory pump could be a temporary solution if the existing one is deemed inadequate. 4. **Boiler Settings:** While less likely, some boilers have internal flow rate or balancing settings that could affect specific radiators. Check your boiler manual and consult a qualified engineer to explore this possibility. **Recommendations:** 1. **Consult a qualified heating engineer:** A professional can perform a thorough diagnosis and determine the root cause of the problem. They have the tools and expertise to measure flow rates, pressure, and test individual components. 2. **Consider a temporary circulatory pump:** If the engineer confirms pump inadequacy, a temporary pump can be installed to verify if it resolves the issue before committing to a permanent installation. 3. **Exhaust other options:** Before resorting to extensive pipework changes, explore all other possibilities like TRV replacements, adjusting boiler settings (if applicable), and ensuring proper balancing by the engineer. **Advice:** * **Don't lose hope:** This can be a complex issue, but with the right diagnosis and approach, your issue can be resolved. * **Communicate clearly with your contractor:** Ensure they understand your concerns and are committed to finding a solution. * **Document everything:** Keep track of any repairs, replacements, and communication with the contractor for future reference. Remember, DIY solutions for gas and heating systems are never recommended. Always involve a qualified and Gas Safe registered engineer to ensure safety and proper functioning of your boiler and radiators. I hope this analysis and recommendations help you find the best solution for your heating issue. Good luck!

I've had a simular situation and found a filter inside the boiler that was blocked I don't no if this may help Also once I found one of the pump valves only partially open

Something doesn’t seem right here, it’s not something I would be exploring if I wasn’t qualified or have enough experience, I’d definitely pay a qualified engineer who has experience in breakdowns.

I would like to add some some other solutions. . Consider to add chemical cleaner to the system and run it for a while. . Close the radiator that already working one by one to force the hot water down pipes to the ones not working, if the problem persist, the pipe that lead to the radiator might be blocked or the radiator. . Test the pressure of the boiler or the pipes sizeing running from the boiler.